src/cpl_query/base/queryable_abc.py

@@ -5,7 +5,7 @@ from typing import Optional, Callable, Union
 class QueryableABC(ABC):
 
     @abstractmethod
-    def all(self, func: Callable) -> bool:
+    def all(self, _func: Callable) -> bool:
         r"""Checks if every element of list equals result found by function
 
         Parameter
@@ -20,7 +20,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def any(self, func: Callable) -> bool:
+    def any(self, _func: Callable) -> bool:
         r"""Checks if list contains result found by function
 
         Parameter
@@ -35,7 +35,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def average(self, func: Callable = None) -> Union[int, float, complex]:
+    def average(self, _func: Callable) -> Union[int, float, complex]:
         r"""Returns average value of list
 
         Parameter
@@ -65,7 +65,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def count(self, func: Callable = None) -> int:
+    def count(self, _func: Callable = None) -> int:
         r"""Returns length of list or count of found elements
 
         Parameter
@@ -80,7 +80,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def distinct(self, func: Callable = None) -> 'QueryableABC':
+    def distinct(self, _func: Callable = None) -> 'QueryableABC':
         r"""Returns list without redundancies
 
         Parameter
@@ -124,26 +124,6 @@ class QueryableABC(ABC):
         """
         pass
 
-    @abstractmethod
-    def last(self) -> any:
-        r"""Returns last element
-
-        Returns
-        -------
-            Last element of list: any
-        """
-        pass
-
-    @abstractmethod
-    def last_or_default(self) -> any:
-        r"""Returns last element or None
-
-        Returns
-        -------
-            Last element of list: Optional[any]
-        """
-        pass
-
     @abstractmethod
     def first(self) -> any:
         r"""Returns first element
@@ -165,7 +145,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def for_each(self, func: Callable):
+    def for_each(self, _func: Callable):
         r"""Runs given function for each element of list
 
         Parameter
@@ -176,8 +156,27 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def max(self, func: Callable = None) -> Union[int, float, complex]:
+    def last(self) -> any:
-        r"""Returns highest value
+        r"""Returns last element
+
+        Returns
+        -------
+            Last element of list: any
+        """
+        pass
+
+    @abstractmethod
+    def last_or_default(self) -> any:
+        r"""Returns last element or None
+
+        Returns
+        -------
+            Last element of list: Optional[any]
+        """
+        pass
+    @abstractmethod
+    def max(self, _func: Callable) -> Union[int, float, complex]:
+        r"""Returns the highest value
 
         Parameter
         ---------
@@ -191,8 +190,19 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def min(self, func: Callable = None) -> Union[int, float, complex]:
+    def median(self) -> Union[int, float]:
-        r"""Returns highest value
+        r"""Return the median value of data elements
+
+        Returns
+        -------
+            Union[int, float]
+        """
+        pass
+
+
+    @abstractmethod
+    def min(self, _func: Callable) -> Union[int, float, complex]:
+        r"""Returns the lowest value
 
         Parameter
         ---------
@@ -206,7 +216,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def order_by(self, func: Callable) -> 'QueryableABC':
+    def order_by(self, _func: Callable) -> 'QueryableABC':
         r"""Sorts elements by function in ascending order
 
         Parameter
@@ -221,7 +231,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def order_by_descending(self, func: Callable) -> 'QueryableABC':
+    def order_by_descending(self, _func: Callable) -> 'QueryableABC':
         r"""Sorts elements by function in descending order
 
         Parameter
@@ -321,7 +331,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def sum(self, func: Callable = None) -> Union[int, float, complex]:
+    def sum(self, _func: Callable) -> Union[int, float, complex]:
         r"""Sum of all values
 
         Parameter
@@ -366,7 +376,7 @@ class QueryableABC(ABC):
         pass
 
     @abstractmethod
-    def where(self, func: Callable) -> 'QueryableABC':
+    def where(self, _func: Callable) -> 'QueryableABC':
         r"""Select element by function
 
         Parameter

src/cpl_query/base/sequence_abc.py

@@ -0,0 +1,50 @@
+from abc import abstractmethod, ABC
+from typing import Union
+
+from cpl_query.base.sequence_values import SequenceValues
+
+
+class SequenceABC(ABC):
+
+    @abstractmethod
+    def __init__(self, t: type = None, values: Union[list, iter] = None):
+        ABC.__init__(self)
+
+        if t == any:
+            t = None
+        elif t is None and values is not None:
+            t = type(values[0])
+
+        self._type = t
+        self._values = SequenceValues(values, t)
+
+    def __len__(self):
+        return len(self._values)
+
+    def __iter__(self):
+        return iter(self._values)
+
+    def next(self):
+        return next(self._values)
+
+    def __next__(self):
+        return self.next()
+
+    def __repr__(self):
+        return f'<{type(self).__name__} {list(self).__repr__()}>'
+
+    @property
+    def type(self) -> type:
+        return self._type
+
+    def reset(self):
+        self._values.reset()
+
+    def to_list(self) -> list:
+        r"""Converts :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC` to :class: `list`
+
+        Returns
+        -------
+            :class: `list`
+        """
+        return [x for x in self]

src/cpl_query/base/sequence_values.py

@@ -0,0 +1,55 @@
+import io
+import itertools
+
+from cpl_query.exceptions import IndexOutOfRangeException
+
+
+class SequenceEnd:
+
+    def __init__(self):
+        self.is_ended = False
+
+    def set_end(self, value: bool) -> 'SequenceEnd':
+        self.is_ended = value
+        return self
+
+
+class SequenceValues:
+    def __init__(self, data, _t: type):
+        if data is None:
+            data = []
+
+        if not hasattr(data, '__iter__'):
+            raise TypeError(f'{type(self).__name__} must be instantiated with an iterable object')
+
+        self._data = []
+        for element in data:
+            if _t is not None and type(element) != _t and not isinstance(type(element), _t) and not issubclass(type(element), _t):
+                raise Exception(f'Unexpected type: {type(element)}\nExpected type: {_t}')
+            self._data.append(element)
+        self._index = 0
+        self._len = sum(1 for item in self._data)
+        self._cycle = itertools.cycle(self._data)
+
+    def __len__(self):
+        return self._len
+
+    def __iter__(self):
+        i = 0
+        while i < len(self):
+            yield next(self._cycle)
+            i += 1
+
+    def __next__(self):
+        if self._index >= len(self):
+            raise IndexOutOfRangeException()
+        self._index += 1
+
+        return self.next()
+
+    def next(self):
+        return next(self._cycle)
+
+    def reset(self):
+        self._index = 0
+        self._cycle = itertools.cycle(self._data)

src/cpl_query/cpl-query.json

@@ -4,7 +4,7 @@
     "Version": {
       "Major": "2022",
       "Minor": "10",
-      "Micro": "2"
+      "Micro": "9"
     },
     "Author": "Sven Heidemann",
     "AuthorEmail": "sven.heidemann@sh-edraft.de",

src/cpl_query/enumerable/enumerable.py

@@ -0,0 +1,333 @@
+from typing import Union, Callable, Optional, Iterable
+
+from cpl_query._helper import is_number
+from cpl_query.base.sequence_values import SequenceValues
+from cpl_query.enumerable.enumerable_abc import EnumerableABC
+from cpl_query.enumerable.ordered_enumerable_abc import OrderedEnumerableABC
+from cpl_query.exceptions import ArgumentNoneException, ExceptionArgument, InvalidTypeException, IndexOutOfRangeException
+
+
+def _default_lambda(x: object):
+    return x
+
+
+class Enumerable(EnumerableABC):
+    r"""Implementation of :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC`
+    """
+
+    def __init__(self, t: type = None, values: Union[list, iter] = None):
+        EnumerableABC.__init__(self, t, values)
+
+    def all(self, _func: Callable = None) -> bool:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = self.where(_func)
+        return len(result) == len(self)
+
+    def any(self, _func: Callable = None) -> bool:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = self.where(_func)
+        return len(result) > 0
+
+    def average(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return float(self.sum(_func)) / float(self.count())
+
+    def contains(self, _value: object) -> bool:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _value is None:
+            raise ArgumentNoneException(ExceptionArgument.value)
+
+        return _value in self
+
+    def count(self, _func: Callable = None) -> int:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            return len(self)
+
+        return len(self.where(_func))
+
+    def distinct(self, _func: Callable = None) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = Enumerable()
+        known_values = []
+        for element in self:
+            value = _func(element)
+            if value in known_values:
+                continue
+
+            known_values.append(value)
+            result.add(element)
+
+        return result
+
+    def element_at(self, _index: int) -> any:
+        self.reset()
+        while _index >= 0:
+            current = self.next()
+            if _index == 0:
+                return current
+            _index -= 1
+
+    def element_at_or_default(self, _index: int) -> any:
+        try:
+            return self.element_at(_index)
+        except IndexOutOfRangeException:
+            return None
+
+    @staticmethod
+    def empty() -> 'EnumerableABC':
+        r"""Returns an empty enumerable
+
+        Returns
+        -------
+            Enumerable object that contains no elements
+        """
+        return Enumerable()
+
+    def first(self: EnumerableABC, _func=None) -> any:
+        if _func is not None:
+            return self.where(_func).element_at(0)
+        return self.element_at(0)
+
+    def first_or_default(self: EnumerableABC, _func=None) -> Optional[any]:
+        if _func is not None:
+            return self.where(_func).element_at_or_default(0)
+        return self.element_at_or_default(0)
+
+    def for_each(self, _func: Callable = None):
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        for element in self:
+            _func(element)
+
+    def last(self: EnumerableABC) -> any:
+        return self.element_at(self.count() - 1)
+
+    def last_or_default(self: EnumerableABC) -> Optional[any]:
+        return self.element_at_or_default(self.count() - 1)
+
+    def max(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return _func(max(self, key=_func))
+
+    def median(self, _func=None) -> Union[int, float]:
+        if _func is None:
+            _func = _default_lambda
+        result = self.order_by(_func).select(_func).to_list()
+        length = len(result)
+        i = int(length / 2)
+        return (
+            result[i]
+            if length % 2 == 1
+            else (float(result[i - 1]) + float(result[i])) / float(2)
+        )
+
+    def min(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return _func(min(self, key=_func))
+
+    def order_by(self, _func: Callable = None) -> OrderedEnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        from cpl_query.enumerable.ordered_enumerable import OrderedEnumerable
+        return OrderedEnumerable(self.type, _func, sorted(self, key=_func))
+
+    def order_by_descending(self, _func: Callable = None) -> OrderedEnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        from cpl_query.enumerable.ordered_enumerable import OrderedEnumerable
+        return OrderedEnumerable(self.type, _func, sorted(self, key=_func, reverse=True))
+
+    @staticmethod
+    def range(start: int, length: int) -> 'EnumerableABC':
+        return Enumerable(int, range(start, start + length, 1))
+
+    def reverse(self: EnumerableABC) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        return Enumerable(self.type, list(reversed(self.to_list())))
+
+    def select(self, _func: Callable = None) -> EnumerableABC:
+        if _func is None:
+            _func = _default_lambda
+
+        result = Enumerable()
+        result.extend(_func(_o) for _o in self)
+        return result
+
+    def select_many(self, _func: Callable = None) -> EnumerableABC:
+        if _func is None:
+            _func = _default_lambda
+
+        result = Enumerable()
+        # The line below is pain. I don't understand anything of it...
+        # written on 09.11.2022 by Sven Heidemann
+        elements = [_a for _o in self for _a in _func(_o)]
+
+        result.extend(elements)
+        return result
+
+    def single(self: EnumerableABC) -> any:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) > 1:
+            raise IndexError('Found more than one element')
+        elif len(self) == 0:
+            raise IndexOutOfRangeException(f'{type(self).__name__} is empty')
+
+        return self.element_at(0)
+
+    def single_or_default(self: EnumerableABC) -> Optional[any]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) > 1:
+            raise IndexError('Found more than one element')
+        elif len(self) == 0:
+            return None
+
+        return self.element_at(0)
+
+    def skip(self, _index: int) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        _list = self.to_list()
+
+        if _index >= len(_list):
+            raise IndexOutOfRangeException()
+
+        return Enumerable(self.type, _list[_index:])
+
+    def skip_last(self, _index: int) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        index = len(self) - _index
+
+        if index >= len(self) or index < 0:
+            raise IndexOutOfRangeException()
+
+        return self.take(len(self) - _index)
+
+    def take(self, _index: int) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        _list = self.to_list()
+
+        if _index >= len(_list):
+            raise IndexOutOfRangeException()
+
+        return Enumerable(self.type, _list[:_index])
+
+    def take_last(self, _index: int) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        _list = self.to_list()
+
+        index = len(_list) - _index
+
+        if index >= len(_list) or index < 0:
+            raise IndexOutOfRangeException()
+
+        return self.skip(index)
+
+    def sum(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return sum([_func(x) for x in self])
+
+    def where(self, _func: Callable = None) -> EnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = Enumerable(self.type)
+        for element in self:
+            if _func(element):
+                result.add(element)
+
+        return result

src/cpl_query/enumerable/enumerable_abc.py

@@ -1,19 +1,18 @@
-import itertools
 from abc import abstractmethod
-from typing import Union
+from typing import Iterable
 
-from cpl_query.enumerable.enumerable_values import EnumerableValues
+from cpl_query.base.queryable_abc import QueryableABC
+from cpl_query.base.sequence_abc import SequenceABC
+from cpl_query.base.sequence_values import SequenceValues
 
 
-class EnumerableABC:
+class EnumerableABC(SequenceABC, QueryableABC):
+    r"""ABC to define functions on list
+    """
 
     @abstractmethod
-    def __init__(self, t: type = None, values: Union[list, iter] = None):
+    def __init__(self, t: type = None, values: Iterable = None):
-        if t == any:
+        SequenceABC.__init__(self, t, values)
-            t = None
-        self._type = t
-
-        self._values = EnumerableValues(values)
         self._remove_error_check = True
 
     def set_remove_error_check(self, _value: bool):
@@ -21,44 +20,6 @@ class EnumerableABC:
         """
         self._remove_error_check = _value
 
-    def __len__(self):
-        return len(self._values)
-
-    def __iter__(self):
-        return iter(self._values)
-
-    def next(self):
-        return next(self._values)
-
-    def __next__(self):
-        return self.next()
-
-    def __getitem__(self, n) -> object:
-        r"""Gets item in enumerable at specified zero-based index
-
-        Parameter
-        --------
-            n: the index of the item to get
-
-        Returns
-        -------
-            The element at the specified index.
-
-        Raises
-        ------
-            IndexError if n > number of elements in the iterable
-        """
-        for i, e in enumerate(self):
-            if i == n:
-                return e
-
-    def __repr__(self):
-        return f'<EnumerableABC {list(self).__repr__()}>'
-
-    @property
-    def type(self) -> type:
-        return self._type
-
     def add(self, __object: object) -> None:
         r"""Adds an element to the enumerable.
         """
@@ -68,16 +29,7 @@ class EnumerableABC:
         if len(self) == 0 and self._type is None:
             self._type = type(__object)
 
-        self._values = EnumerableValues([*self._values, __object])
+        self._values = SequenceValues([*self._values, __object], self._type)
-
-    def count(self) -> int:
-        r"""Returns count of  elements
-
-        Returns
-        -------
-            int
-        """
-        return sum(1 for element in self)
 
     def clear(self):
         r"""Removes all elements
@@ -85,19 +37,16 @@ class EnumerableABC:
         del self._values
         self._values = []
 
-    @staticmethod
+    def extend(self, __list: Iterable) -> 'EnumerableABC':
-    def empty():
+        r"""Adds elements of given list to enumerable
-        r"""Returns an empty enumerable
 
-        Returns
+        Parameter
-        -------
+        ---------
-            Enumerable object that contains no elements
+            __enumerable: :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC`
+                index
         """
-        return EnumerableABC()
+        self._values = SequenceValues([*self._values, *__list], self._type)
-
+        return self
-    @staticmethod
-    def range(start: int, length: int) -> 'EnumerableABC':
-        return EnumerableABC(int, range(start, start + length, 1))
 
     def remove(self, __object: object) -> None:
         r"""Removes element from list
@@ -115,13 +64,4 @@ class EnumerableABC:
             raise Exception('Element not found')
 
         # self._values.remove(__object)
-        self._values = EnumerableValues([x for x in self.to_list() if x != __object])
+        self._values = SequenceValues([x for x in self.to_list() if x != __object], self._type)
-
-    def to_list(self) -> list:
-        r"""Converts :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC` to :class: `list`
-
-        Returns
-        -------
-            :class: `list`
-        """
-        return [x for x in self]

src/cpl_query/enumerable/enumerable_values.py

@@ -1,31 +0,0 @@
-import io
-import itertools
-
-
-class EnumerableValues:
-    def __init__(self, data):
-        if data is None:
-            data = []
-
-        if not hasattr(data, '__iter__'):
-            raise TypeError('RepeatableIterable must be instantiated with an iterable object')
-
-        is_generator = hasattr(data, 'gi_running') or isinstance(data, io.TextIOBase)
-        self._data = data if not is_generator else [i for i in data]
-        self._len = sum(1 for item in self._data)
-        self.cycle = itertools.cycle(self._data)
-
-    def __len__(self):
-        return self._len
-
-    def __iter__(self):
-        i = 0
-        while i < len(self):
-            yield next(self.cycle)
-            i += 1
-
-    def __next__(self):
-        return self.next()
-
-    def next(self):
-        return next(self.cycle)

src/cpl_query/enumerable/ordered_enumerable.py

@@ -0,0 +1,36 @@
+from collections.abc import Callable
+from typing import Iterable
+
+from cpl_query.enumerable.enumerable import Enumerable
+from cpl_query.enumerable.ordered_enumerable_abc import OrderedEnumerableABC
+from cpl_query.exceptions import ArgumentNoneException, ExceptionArgument
+
+
+class OrderedEnumerable(Enumerable, OrderedEnumerableABC):
+    r"""Implementation of :class: `cpl_query.extension.Enumerable` `cpl_query.extension.OrderedEnumerableABC`
+    """
+
+    def __init__(self, _t: type, _func: Callable = None, _values: Iterable = None):
+        Enumerable.__init__(self, _t)
+        OrderedEnumerableABC.__init__(self, _t, _func, _values)
+
+    def then_by(self: OrderedEnumerableABC, _func: Callable) -> OrderedEnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
+
+        self._funcs.append(_func)
+
+        return OrderedEnumerable(self.type, _func, sorted(self, key=lambda *args: [f(*args) for f in self._funcs]))
+
+    def then_by_descending(self: OrderedEnumerableABC, _func: Callable) -> OrderedEnumerableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
+
+        self._funcs.append(_func)
+        return OrderedEnumerable(self.type, _func, sorted(self, key=lambda *args: [f(*args) for f in self._funcs], reverse=True))

src/cpl_query/enumerable/ordered_enumerable_abc.py

@@ -0,0 +1,43 @@
+from abc import abstractmethod
+from collections.abc import Callable
+from typing import Iterable
+
+from cpl_query.enumerable.enumerable_abc import EnumerableABC
+
+
+class OrderedEnumerableABC(EnumerableABC):
+
+    @abstractmethod
+    def __init__(self, _t: type, _func: Callable = None, _values: Iterable = None):
+        EnumerableABC.__init__(self, _t, _values)
+        self._funcs: list[Callable] = []
+        if _func is not None:
+            self._funcs.append(_func)
+
+    @abstractmethod
+    def then_by(self, func: Callable) -> 'OrderedEnumerableABC':
+        r"""Sorts OrderedList in ascending order by function
+
+        Parameter
+        ---------
+            func: :class:`Callable`
+            
+        Returns
+        -------
+            list of :class:`cpl_query.extension.OrderedEnumerableABC`
+        """
+        pass
+
+    @abstractmethod
+    def then_by_descending(self, func: Callable) -> 'OrderedEnumerableABC':
+        r"""Sorts OrderedList in descending order by function
+
+        Parameter
+        ---------
+            func: :class:`Callable`
+            
+        Returns
+        -------
+            list of :class:`cpl_query.extension.OrderedEnumerableABC`
+        """
+        pass

src/cpl_query/exceptions.py

@@ -23,8 +23,8 @@ class IndexOutOfRangeException(Exception):
     r"""Exception when index is out of range
     """
 
-    def __init__(self):
+    def __init__(self, err: str = None):
-        Exception.__init__(self, f'List index out of range')
+        Exception.__init__(self, f'List index out of range' if err is None else err)
 
 
 class InvalidTypeException(Exception):

src/cpl_query/extension/lazy_list.py

@@ -1,9 +0,0 @@
-from cpl_query.enumerable.enumerable_abc import EnumerableABC
-
-
-class LazyList(EnumerableABC):
-    r"""Implementation of :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC`
-    """
-
-    def __init__(self, t: type = None, values: list = None):
-        EnumerableABC.__init__(self, t, values)

src/cpl_query/iterable/iterable.py

@@ -1,8 +1,13 @@
 from typing import Callable, Optional, Union
 
+from cpl_query._helper import is_number
+from cpl_query.exceptions import ArgumentNoneException, ExceptionArgument, InvalidTypeException, IndexOutOfRangeException
 from cpl_query.iterable.iterable_abc import IterableABC
 from cpl_query.iterable.ordered_iterable_abc import OrderedIterableABC
-from cpl_query.query import Query
+
+
+def _default_lambda(x: object):
+    return x
 
 
 class Iterable(IterableABC):
@@ -10,97 +15,329 @@ class Iterable(IterableABC):
     def __init__(self, t: type = None, values: list = None):
         IterableABC.__init__(self, t, values)
 
-    def any(self, func: Callable) -> bool:
+    def all(self, _func: Callable = None) -> bool:
-        return Query.any(self, func)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def all(self, func: Callable) -> bool:
+        if _func is None:
-        return Query.all(self, func)
+            _func = _default_lambda
 
-    def average(self, func: Callable = None) -> Union[int, float, complex]:
+        result = self.where(_func)
-        return Query.avg(self, func)
+        return len(result) == len(self)
 
-    def contains(self, value: object) -> bool:
+    def any(self, _func: Callable = None) -> bool:
-        return Query.contains(self, value)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def count(self, func: Callable = None) -> int:
+        if _func is None:
-        return Query.count(self, func)
+            _func = _default_lambda
 
-    def distinct(self, func: Callable = None) -> IterableABC:
+        result = self.where(_func)
-        return self.__to_self(Query.distinct(self, func))
+        return len(result) > 0
 
-    def element_at(self, index: int) -> any:
+    def average(self, _func: Callable = None) -> Union[int, float, complex]:
-        return Query.element_at(self, index)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def element_at_or_default(self, index: int) -> Optional[any]:
+        if _func is None and not is_number(self.type):
-        return Query.element_at_or_default(self, index)
+            raise InvalidTypeException()
 
-    def last(self) -> any:
+        if _func is None:
-        return Query.last(self)
+            _func = _default_lambda
 
-    def last_or_default(self) -> Optional[any]:
+        return float(self.sum(_func)) / float(self.count())
-        return Query.last_or_default(self)
 
-    def first(self) -> any:
+    def contains(self, _value: object) -> bool:
-        return Query.first(self)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def first_or_default(self) -> Optional[any]:
+        if _value is None:
-        return Query.first_or_default(self)
+            raise ArgumentNoneException(ExceptionArgument.value)
 
-    def for_each(self, func: Callable):
+        return _value in self
-        Query.for_each(self, func)
 
-    def max(self, func: Callable = None) -> Union[int, float, complex]:
+    def count(self, _func: Callable = None) -> int:
-        return Query.max(self, func)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def min(self, func: Callable = None) -> Union[int, float, complex]:
+        if _func is None:
-        return Query.min(self, func)
+            return len(self)
+
+        return len(self.where(_func))
+
+    def distinct(self, _func: Callable = None) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = Iterable()
+        known_values = []
+        for element in self:
+            value = _func(element)
+            if value in known_values:
+                continue
+
+            known_values.append(value)
+            result.append(element)
+
+        return result
+
+    def element_at(self, _index: int) -> any:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        return self[_index]
+
+    def element_at_or_default(self, _index: int) -> any:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        try:
+            return self[_index]
+        except IndexError:
+            return None
+
+    def first(self: IterableABC) -> any:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) == 0:
+            raise IndexOutOfRangeException()
+
+        return self[0]
+
+    def first_or_default(self: IterableABC) -> Optional[any]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) == 0:
+            return None
+
+        return self[0]
+
+    def last(self: IterableABC) -> any:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) == 0:
+            raise IndexOutOfRangeException()
+
+        return self[len(self) - 1]
+
+    def last_or_default(self: IterableABC) -> Optional[any]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if len(self) == 0:
+            return None
+
+        return self[len(self) - 1]
+
+    def for_each(self, _func: Callable = None):
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
+
+        for element in self:
+            _func(element)
+
+    def max(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return _func(max(self, key=_func))
+
+    def median(self, _func=None) -> Union[int, float]:
+        if _func is None:
+            _func = _default_lambda
+        result = self.order_by(_func).select(_func).to_list()
+        length = len(result)
+        i = int(length / 2)
+        return (
+            result[i]
+            if length % 2 == 1
+            else (float(result[i - 1]) + float(result[i])) / float(2)
+        )
+
+    def min(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return _func(min(self, key=_func))
+
+    def order_by(self, _func: Callable = None) -> OrderedIterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
 
-    def order_by(self, func: Callable) -> OrderedIterableABC:
-        res = Query.order_by(self, func)
         from cpl_query.iterable.ordered_iterable import OrderedIterable
-        res.__class__ = OrderedIterable
+        return OrderedIterable(self.type, _func, sorted(self, key=_func))
-        return res
+
+    def order_by_descending(self, _func: Callable = None) -> OrderedIterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            _func = _default_lambda
 
-    def order_by_descending(self, func: Callable) -> OrderedIterableABC:
-        res = Query.order_by_descending(self, func)
         from cpl_query.iterable.ordered_iterable import OrderedIterable
-        res.__class__ = OrderedIterable
+        return OrderedIterable(self.type, _func, sorted(self, key=_func, reverse=True))
-        return res
 
-    def reverse(self) -> IterableABC:
+    def reverse(self: IterableABC) -> IterableABC:
-        return Query.reverse(self)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def single(self) -> any:
+        return Iterable().extend(reversed(self.to_list()))
-        return Query.single(self)
 
-    def single_or_default(self) -> Optional[any]:
+    def select(self, _func: Callable = None) -> IterableABC:
-        return Query.single_or_default(self)
+        if _func is None:
+            _func = _default_lambda
 
-    def select(self, _f: Callable) -> IterableABC:
+        result = Iterable()
-        return self.__to_self(Query.select(self, _f))
+        result.extend(_func(_o) for _o in self)
+        return result
 
-    def select_many(self, _f: Callable) -> IterableABC:
+    def select_many(self, _func: Callable = None) -> IterableABC:
-        return self.__to_self(Query.select_many(self, _f))
+        if _func is None:
+            _func = _default_lambda
 
-    def skip(self, index: int) -> IterableABC:
+        result = Iterable()
-        return self.__to_self(Query.skip(self, index))
+        # The line below is pain. I don't understand anything of it...
+        # written on 09.11.2022 by Sven Heidemann
+        elements = [_a for _o in self for _a in _func(_o)]
 
-    def skip_last(self, index: int) -> IterableABC:
+        result.extend(elements)
-        return self.__to_self(Query.skip_last(self, index))
+        return result
 
-    def sum(self, func: Callable = None) -> Union[int, float, complex]:
+    def single(self: IterableABC) -> any:
-        return Query.sum(self, func)
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    def take(self, index: int) -> IterableABC:
+        if len(self) > 1:
-        return self.__to_self(Query.take(self, index))
+            raise Exception('Found more than one element')
+        elif len(self) == 0:
+            raise Exception('Found no element')
 
-    def take_last(self, index: int) -> IterableABC:
+        return self[0]
-        return self.__to_self(Query.take_last(self, index))
 
-    def where(self, func: Callable) -> IterableABC:
+    def single_or_default(self: IterableABC) -> Optional[any]:
-        return self.__to_self(Query.where(self, func))
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
 
-    @staticmethod
+        if len(self) > 1:
-    def __to_self(obj: IterableABC) -> IterableABC:
+            raise Exception('Index out of range')
-        obj.__class__ = Iterable
+        elif len(self) == 0:
-        return obj
+            return None
+
+        return self[0]
+
+    def skip(self, _index: int) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        if _index >= len(self):
+            raise IndexOutOfRangeException()
+
+        return Iterable(self.type, values=self[_index:])
+
+    def skip_last(self, _index: int) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        index = len(self) - _index
+
+        if index >= len(self) or index < 0:
+            raise IndexOutOfRangeException()
+
+        result = Iterable()
+        result.extend(self[:index])
+        return result
+
+    def take(self, _index: int) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        if _index >= len(self):
+            raise IndexOutOfRangeException()
+
+        result = Iterable()
+        result.extend(self[:_index])
+        return result
+
+    def take_last(self, _index: int) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _index is None:
+            raise ArgumentNoneException(ExceptionArgument.index)
+
+        index = len(self) - _index
+
+        if index >= len(self) or index < 0:
+            raise IndexOutOfRangeException()
+
+        result = Iterable()
+        result.extend(self[index:])
+        return result
+
+    def sum(self, _func: Callable = None) -> Union[int, float, complex]:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None and not is_number(self.type):
+            raise InvalidTypeException()
+
+        if _func is None:
+            _func = _default_lambda
+
+        return sum([_func(x) for x in self])
+
+    def where(self, _func: Callable = None) -> IterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
+
+        if _func is None:
+            _func = _default_lambda
+
+        result = Iterable(self.type)
+        for element in self:
+            if _func(element):
+                result.append(element)
+
+        return result

src/cpl_query/iterable/iterable_abc.py

@@ -1,33 +1,38 @@
-from abc import ABC, abstractmethod
+from abc import abstractmethod
-from typing import Optional, Callable, Union, Iterable
+from typing import Iterable
 
 from cpl_query.base.queryable_abc import QueryableABC
-from cpl_query.enumerable.enumerable_abc import EnumerableABC
+from cpl_query.base.sequence_abc import SequenceABC
+from cpl_query.base.sequence_values import SequenceValues
 
 
-class IterableABC(QueryableABC, list):
+class IterableABC(SequenceABC, QueryableABC):
     r"""ABC to define functions on list
     """
 
     @abstractmethod
     def __init__(self, t: type = None, values: list = None):
-        list.__init__(self)
+        SequenceABC.__init__(self, t, values)
 
-        if t == any:
+    def __getitem__(self, n) -> object:
-            t = None
+        r"""Gets item in enumerable at specified zero-based index
-        self._type = t
 
-        if values is not None:
+        Parameter
-            for value in values:
+        --------
-                self.append(value)
+            n: the index of the item to get
 
-    @property
+        Returns
-    def type(self) -> type:
+        -------
-        return self._type
+            The element at the specified index.
+
+        Raises
+        ------
+            IndexError if n > number of elements in the iterable
+        """
+        return list.__getitem__(self.to_list(), n)
 
     def append(self, __object: object) -> None:
         r"""Adds element to list
-
         Parameter
         ---------
             __object: :class:`object`
@@ -39,11 +44,10 @@ class IterableABC(QueryableABC, list):
         if len(self) == 0 and self._type is None:
             self._type = type(__object)
 
-        super().append(__object)
+        self._values = SequenceValues([*self._values, __object], self._type)
 
     def extend(self, __iterable: Iterable) -> 'IterableABC':
         r"""Adds elements of given list to list
-
         Parameter
         ---------
             __iterable: :class: `cpl_query.extension.iterable.Iterable`
@@ -53,12 +57,3 @@ class IterableABC(QueryableABC, list):
             self.append(value)
 
         return self
-
-    def to_list(self) -> list:
-        r"""Converts :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC` to :class: `list`
-
-        Returns
-        -------
-            :class: `list`
-        """
-        return list(self)

src/cpl_query/iterable/ordered_iterable.py

@@ -1,22 +1,35 @@
 from collections.abc import Callable
 
+from cpl_query.exceptions import ArgumentNoneException, ExceptionArgument
 from cpl_query.iterable.iterable import Iterable
 from cpl_query.iterable.ordered_iterable_abc import OrderedIterableABC
-from cpl_query.query import Query
 
 
 class OrderedIterable(Iterable, OrderedIterableABC):
     r"""Implementation of :class: `cpl_query.extension.Iterable` `cpl_query.extension.OrderedIterableABC`
     """
 
-    def __init__(self, _t: type = None):
+    def __init__(self, _t: type, _func: Callable = None, _values: Iterable = None):
         Iterable.__init__(self, _t)
-        OrderedIterableABC.__init__(self, _t)
+        OrderedIterableABC.__init__(self, _t, _func, _values)
 
-    def then_by(self, _func: Callable) -> OrderedIterableABC:
+    def then_by(self: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
-        self._funcs.append(_func)
+        if self is None:
-        return Query.then_by(self, lambda *args: [f(*args) for f in self._funcs])
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
 
-    def then_by_descending(self, _func: Callable) -> OrderedIterableABC:
         self._funcs.append(_func)
-        return Query.then_by_descending(self, lambda *args: [f(*args) for f in self._funcs])
+
+        return OrderedIterable(self.type, _func, sorted(self, key=lambda *args: [f(*args) for f in self._funcs]))
+
+    def then_by_descending(self: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
+        if self is None:
+            raise ArgumentNoneException(ExceptionArgument.list)
+
+        if _func is None:
+            raise ArgumentNoneException(ExceptionArgument.func)
+
+        self._funcs.append(_func)
+        return OrderedIterable(self.type, _func, sorted(self, key=lambda *args: [f(*args) for f in self._funcs], reverse=True))

src/cpl_query/iterable/ordered_iterable_abc.py

@@ -1,5 +1,6 @@
 from abc import abstractmethod
 from collections.abc import Callable
+from typing import Iterable
 
 from cpl_query.iterable.iterable_abc import IterableABC
 
@@ -7,8 +8,8 @@ from cpl_query.iterable.iterable_abc import IterableABC
 class OrderedIterableABC(IterableABC):
 
     @abstractmethod
-    def __init__(self, _t: type, _func: Callable = None):
+    def __init__(self, _t: type, _func: Callable = None, _values: Iterable = None):
-        IterableABC.__init__(self, _t)
+        IterableABC.__init__(self, _t, _values)
         self._funcs: list[Callable] = []
         if _func is not None:
             self._funcs.append(_func)
@@ -23,7 +24,7 @@ class OrderedIterableABC(IterableABC):
             
         Returns
         -------
-            list of :class:`cpl_query.extension.OrderedIterableABC`
+            list of :class:`cpl_query.iterable.ordered_iterable_abc.OrderedIterableABC`
         """
         pass
 
@@ -37,6 +38,6 @@ class OrderedIterableABC(IterableABC):
             
         Returns
         -------
-            list of :class:`cpl_query.extension.OrderedIterableABC`
+            list of :class:`cpl_query.iterable.ordered_iterable_abc.OrderedIterableABC`
         """
         pass

src/cpl_query/query.py

@@ -1,405 +0,0 @@
-from typing import Callable, Union, Optional
-
-from cpl_query._helper import is_number
-from cpl_query.exceptions import ArgumentNoneException, ExceptionArgument, InvalidTypeException, IndexOutOfRangeException
-from cpl_query.iterable.iterable_abc import IterableABC
-from cpl_query.iterable.ordered_iterable_abc import OrderedIterableABC
-
-
-class Query:
-
-    @staticmethod
-    def all(_list: IterableABC, _func: Callable) -> bool:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        result = Query.where(_list, _func)
-        return len(result) == len(_list)
-
-    @staticmethod
-    def any(_list: IterableABC, _func: Callable) -> bool:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        result = Query.where(_list, _func)
-        return len(result) > 0
-
-    @staticmethod
-    def avg(_list: IterableABC, _func: Callable) -> Union[int, float, complex]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None and not is_number(_list.type):
-            raise InvalidTypeException()
-
-        average = 0
-        count = len(_list)
-
-        for element in _list:
-            if _func is not None:
-                value = _func(element)
-
-            else:
-                value = element
-
-            average += value
-
-        return average / count
-
-    @staticmethod
-    def contains(_list: IterableABC, _value: object) -> bool:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _value is None:
-            raise ArgumentNoneException(ExceptionArgument.value)
-
-        return _value in _list
-
-    @staticmethod
-    def count(_list: IterableABC, _func: Callable = None) -> int:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            return len(_list)
-
-        return len(Query.where(_list, _func))
-
-    @staticmethod
-    def distinct(_list: IterableABC, _func: Callable) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        result = IterableABC()
-        known_values = []
-        for element in _list:
-            value = _func(element)
-            if value in known_values:
-                continue
-
-            known_values.append(value)
-            result.append(element)
-
-        return result
-
-    @staticmethod
-    def element_at(_list: IterableABC, _index: int) -> any:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        return _list[_index]
-
-    @staticmethod
-    def element_at_or_default(_list: IterableABC, _index: int) -> any:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        try:
-            return _list[_index]
-        except IndexError:
-            return None
-
-    @staticmethod
-    def first(_list: IterableABC) -> any:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) == 0:
-            raise IndexOutOfRangeException()
-
-        return _list[0]
-
-    @staticmethod
-    def first_or_default(_list: IterableABC) -> Optional[any]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) == 0:
-            return None
-
-        return _list[0]
-
-    @staticmethod
-    def last(_list: IterableABC) -> any:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) == 0:
-            raise IndexOutOfRangeException()
-
-        return _list[len(_list) - 1]
-
-    @staticmethod
-    def last_or_default(_list: IterableABC) -> Optional[any]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) == 0:
-            return None
-
-        return _list[len(_list) - 1]
-
-    @staticmethod
-    def for_each(_list: IterableABC, _func: Callable):
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        for element in _list:
-            _func(element)
-
-    @staticmethod
-    def max(_list: IterableABC, _func: Callable) -> Union[int, float, complex]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None and not is_number(_list.type):
-            raise InvalidTypeException()
-
-        max_value = 0
-        for element in _list:
-            if _func is not None:
-                value = _func(element)
-            else:
-                value = element
-
-            if value > max_value:
-                max_value = value
-
-        return max_value
-
-    @staticmethod
-    def min(_list: IterableABC, _func: Callable) -> Union[int, float, complex]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None and not is_number(_list.type):
-            raise InvalidTypeException()
-
-        min_value = 0
-        is_first = True
-        for element in _list:
-            if _func is not None:
-                value = _func(element)
-            else:
-                value = element
-
-            if is_first:
-                min_value = value
-                is_first = False
-
-            if value < min_value:
-                min_value = value
-
-        return min_value
-
-    @staticmethod
-    def order_by(_list: IterableABC, _func: Callable) -> OrderedIterableABC:
-        result = OrderedIterableABC(_list.type, _func)
-        _list.sort(key=_func)
-        result.extend(_list)
-        return result
-
-    @staticmethod
-    def order_by_descending(_list: IterableABC, _func: Callable) -> OrderedIterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        result = OrderedIterableABC(_list.type, _func)
-        _list.sort(key=_func, reverse=True)
-        result.extend(_list)
-        return result
-
-    @staticmethod
-    def then_by(_list: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        _list.sort(key=_func)
-        return _list
-
-    @staticmethod
-    def then_by_descending(_list: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        _list.sort(key=_func, reverse=True)
-        return _list
-
-    @staticmethod
-    def reverse(_list: IterableABC) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        result = IterableABC()
-        _copied_list = _list.to_list()
-        _copied_list.reverse()
-        for element in _copied_list:
-            result.append(element)
-
-        return result
-
-    @staticmethod
-    def select(_list: IterableABC, _f: Callable) -> any:
-        result = IterableABC()
-        result.extend(_f(_o) for _o in _list)
-        return result
-
-    @staticmethod
-    def select_many(_list: IterableABC, _f: Callable) -> any:
-        result = IterableABC()
-        # The line below is pain. I don't understand anything of it...
-        # written on 09.11.2022 by Sven Heidemann
-        elements = [_a for _o in _list for _a in _f(_o)]
-
-        result.extend(elements)
-        return result
-
-    @staticmethod
-    def single(_list: IterableABC) -> any:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) > 1:
-            raise Exception('Found more than one element')
-        elif len(_list) == 0:
-            raise Exception('Found no element')
-
-        return _list[0]
-
-    @staticmethod
-    def single_or_default(_list: IterableABC) -> Optional[any]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if len(_list) > 1:
-            raise Exception('Index out of range')
-        elif len(_list) == 0:
-            return None
-
-        return _list[0]
-
-    @staticmethod
-    def skip(_list: IterableABC, _index: int) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        if _index >= len(_list):
-            raise IndexOutOfRangeException()
-
-        result = IterableABC()
-        result.extend(_list[_index:])
-        return result
-
-    @staticmethod
-    def skip_last(_list: IterableABC, _index: int) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        index = len(_list) - _index
-
-        if index >= len(_list) or index < 0:
-            raise IndexOutOfRangeException()
-
-        result = IterableABC()
-        result.extend(_list[:index])
-        return result
-
-    @staticmethod
-    def take(_list: IterableABC, _index: int) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        if _index >= len(_list):
-            raise IndexOutOfRangeException()
-
-        result = IterableABC()
-        result.extend(_list[:_index])
-        return result
-
-    @staticmethod
-    def take_last(_list: IterableABC, _index: int) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _index is None:
-            raise ArgumentNoneException(ExceptionArgument.index)
-
-        index = len(_list) - _index
-
-        if index >= len(_list) or index < 0:
-            raise IndexOutOfRangeException()
-
-        result = IterableABC()
-        result.extend(_list[index:])
-        return result
-
-    @staticmethod
-    def sum(_list: IterableABC, _func: Callable) -> Union[int, float, complex]:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None and not is_number(_list.type):
-            raise InvalidTypeException()
-
-        result = 0
-        for element in _list:
-            if _func is not None:
-                value = _func(element)
-            else:
-                value = element
-
-            result += value
-
-        return result
-
-    @staticmethod
-    def where(_list: IterableABC, _func: Callable) -> IterableABC:
-        if _list is None:
-            raise ArgumentNoneException(ExceptionArgument.list)
-
-        if _func is None:
-            raise ArgumentNoneException(ExceptionArgument.func)
-
-        result = IterableABC(_list.type)
-        for element in _list:
-            if _func(element):
-                result.append(element)
-
-        return result

unittests/unittests_query/enumerable_query_test_case.py

@@ -0,0 +1,357 @@
+import string
+import unittest
+from random import randint
+
+from cpl_core.utils import String
+from cpl_query.enumerable.enumerable import Enumerable
+from cpl_query.exceptions import InvalidTypeException, ArgumentNoneException, IndexOutOfRangeException
+from unittests_query.models import User, Address
+
+
+class EnumerableQueryTestCase(unittest.TestCase):
+
+    def setUp(self) -> None:
+        self._tests = Enumerable(User)
+        self._t_user = User(
+            'Test user',
+            Address(
+                'teststr.',
+                15
+            )
+        )
+        self._t_user2 = User(
+            'Test user',
+            Address(
+                'teststr.',
+                14
+            )
+        )
+
+        self._generate_test_data()
+
+    def _generate_test_data(self):
+        for i in range(0, 100):
+            user = User(
+                String.random_string(string.ascii_letters, 8).lower(),
+                Address(
+                    String.random_string(string.ascii_letters, 10).lower(),
+                    randint(1, 10)
+                )
+            )
+
+            self._tests.add(user)
+
+        self._tests.add(self._t_user)
+        self._tests.add(self._t_user2)
+
+    def test_any(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.any(lambda u: u.address.nr == 10)
+        n_res = self._tests.any(lambda u: u.address.nr == 100)
+
+        self.assertTrue(res)
+        self.assertFalse(n_res)
+
+    def test_all(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.all(lambda u: u.address is not None)
+        n_res = self._tests.all(lambda u: u.address.nr == 100)
+
+        self.assertTrue(res)
+        self.assertFalse(n_res)
+
+    def test_avg(self):
+        avg = 0
+        for user in self._tests:
+            avg += user.address.nr
+
+        avg = avg / len(self._tests)
+        res = self._tests.average(lambda u: u.address.nr)
+
+        self.assertEqual(avg, res)
+
+        def invalid():
+            tests = Enumerable(str, ['hello', 'world'])
+            e_res = tests.average()
+
+        self.assertRaises(InvalidTypeException, invalid)
+
+        tests = Enumerable(int, list(range(0, 100)))
+        self.assertEqual(sum(tests) / len(tests), tests.average())
+
+        def wrong2():
+            tests2 = Enumerable(int, values=list(range(0, 100)))
+            e_res = tests2.average(lambda u: u.address.nr)
+
+        self.assertRaises(AttributeError, wrong2)
+
+    def test_contains(self):
+        self.assertTrue(self._tests.contains(self._t_user))
+        self.assertFalse(self._tests.contains(User("Test", None)))
+
+    def test_count(self):
+        self.assertEqual(len(self._tests), self._tests.count())
+        self.assertEqual(1, self._tests.count(lambda u: u == self._t_user))
+
+    def test_distinct(self):
+        res = self._tests.distinct(lambda u: u.address.nr).where(lambda u: u.address.nr == 5)
+        self.assertEqual(1, len(res))
+
+    def test_element_at(self):
+        index = randint(0, len(self._tests) - 1)
+        self.assertEqual(self._tests.element_at(index), self._tests.element_at(index))
+
+        def invalid():
+            result = self._tests.element_at(len(self._tests))
+
+        self.assertRaises(IndexOutOfRangeException, invalid)
+
+    def test_element_at_or_default(self):
+        index = randint(0, len(self._tests) - 1)
+        self.assertEqual(self._tests.element_at(index), self._tests.element_at_or_default(index))
+        self.assertIsNone(self._tests.element_at_or_default(len(self._tests)))
+
+    def test_last(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.where(lambda u: u.address.nr == 10)
+        s_res = self._tests.where(lambda u: u.address.nr == 10).last()
+
+        self.assertEqual(len(res), len(results))
+        self.assertEqual(res.element_at(len(res) - 1), s_res)
+
+    def test_last_or_default(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.where(lambda u: u.address.nr == 10)
+        s_res = self._tests.where(lambda u: u.address.nr == 10).last_or_default()
+        sn_res = self._tests.where(lambda u: u.address.nr == 11).last_or_default()
+
+        self.assertEqual(len(res), len(results))
+        self.assertEqual(res.element_at(len(res) - 1), s_res)
+        self.assertIsNone(sn_res)
+
+    def test_first(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.where(lambda u: u.address.nr == 10)
+        s_res = self._tests.where(lambda u: u.address.nr == 10).first()
+
+        self.assertEqual(len(res), len(results))
+        self.assertEqual(res.element_at(0), s_res)
+
+    def test_first_or_default(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 10:
+                results.append(user)
+
+        res = self._tests.where(lambda u: u.address.nr == 10)
+        s_res = self._tests.where(lambda u: u.address.nr == 10).first_or_default()
+        sn_res = self._tests.where(lambda u: u.address.nr == 11).first_or_default()
+
+        self.assertEqual(len(res), len(results))
+        self.assertEqual(res.element_at(0), s_res)
+        self.assertIsNone(sn_res)
+
+    def test_for_each(self):
+        users = []
+        self._tests.for_each(lambda user: (
+            users.append(user)
+        )
+                             )
+
+        self.assertEqual(len(users), len(self._tests))
+
+    def test_max(self):
+        res = self._tests.max(lambda u: u.address.nr)
+        self.assertEqual(res, self._t_user.address.nr)
+
+        tests = Enumerable(values=list(range(0, 100)))
+        self.assertEqual(99, tests.max())
+
+        def invalid():
+            tests = Enumerable(str, ['hello', 'world'])
+            e_res = tests.average()
+
+        self.assertRaises(InvalidTypeException, invalid)
+
+    def test_min(self):
+        res = self._tests.min(lambda u: u.address.nr)
+        self.assertEqual(1, res)
+
+        tests = Enumerable(values=list(range(0, 100)))
+        self.assertEqual(0, tests.min())
+
+        def invalid():
+            tests = Enumerable(str, ['hello', 'world'])
+            e_res = tests.average()
+
+        self.assertRaises(InvalidTypeException, invalid)
+
+    def test_order_by(self):
+        res = self._tests.order_by(lambda user: user.address.street)
+        res2 = self._tests.order_by(lambda user: user.address.nr).to_list()
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: user.address.street)
+        self.assertEqual(res.to_list(), s_res)
+
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: user.address.nr)
+        self.assertEqual(res2, s_res)
+
+        self.assertEqual(self._t_user, res.where(lambda u: u.address.nr == self._t_user.address.nr).single())
+
+    def test_order_by_descending(self):
+        res = self._tests.order_by_descending(lambda user: user.address.street).to_list()
+        res2 = self._tests.order_by_descending(lambda user: user.address.nr).to_list()
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: user.address.street, reverse=True)
+
+        self.assertEqual(res, s_res)
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: user.address.nr, reverse=True)
+        self.assertEqual(res2, s_res)
+
+    def test_then_by(self):
+        res = self._tests.order_by(lambda user: user.address.street).then_by(lambda user: user.address.nr).to_list()
+
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: (user.address.street, user.address.nr))
+
+        self.assertEqual(res, s_res)
+
+    def test_then_by_descending(self):
+        res = self._tests.order_by_descending(lambda user: user.address.street).then_by_descending(lambda user: user.address.nr).to_list()
+
+        s_res = self._tests.to_list()
+        s_res.sort(key=lambda user: (user.address.street, user.address.nr), reverse=True)
+
+        self.assertEqual(res, s_res)
+
+    def test_reverse(self):
+        res = self._tests.reverse().to_list()
+        l_res = self._tests.to_list()
+        l_res.reverse()
+
+        self.assertEqual(res, l_res)
+
+    def test_select(self):
+        range_list = Enumerable(int, range(0, 100))
+        selected_range = range_list.select(lambda x: x + 1)
+
+        modulo_range = []
+        for x in range(0, 100):
+            if x % 2 == 0:
+                modulo_range.append(x)
+        self.assertEqual(selected_range.to_list(), list(range(1, 101)))
+        self.assertEqual(range_list.where(lambda x: x % 2 == 0).to_list(), modulo_range)
+
+    def test_select_many(self):
+        range_list = Enumerable(int, list(range(0, 100)))
+        selected_range = range_list.select(lambda x: [x, x])
+
+        self.assertEqual(selected_range.to_list(), [[x, x] for x in range(0, 100)])
+        self.assertEqual(selected_range.select_many(lambda x: x).to_list(), [_x for _l in [2 * [x] for x in range(0, 100)] for _x in _l])
+
+        class TestClass:
+            def __init__(self, i, is_sub=False):
+                self.i = i
+                if is_sub:
+                    return
+                self.elements = [TestClass(x, True) for x in range(0, 10)]
+
+        elements = Enumerable(TestClass, [TestClass(i) for i in range(0, 100)])
+        selected_elements = elements.select_many(lambda x: x.elements).select(lambda x: x.i)
+        self.assertEqual(selected_elements.where(lambda x: x == 0).count(), 100)
+
+    def test_single(self):
+        res = self._tests.where(lambda u: u.address.nr == self._t_user.address.nr)
+        s_res = self._tests.where(lambda u: u.address.nr == self._t_user.address.nr).single()
+
+        self.assertEqual(len(res), 1)
+        self.assertEqual(self._t_user, s_res)
+
+    def test_single_or_default(self):
+        res = self._tests.where(lambda u: u.address.nr == self._t_user.address.nr)
+        s_res = self._tests.where(lambda u: u.address.nr == self._t_user.address.nr).single_or_default()
+        sn_res = self._tests.where(lambda u: u.address.nr == self._t_user.address.nr + 1).single_or_default()
+
+        self.assertEqual(len(res), 1)
+        self.assertEqual(self._t_user, s_res)
+        self.assertIsNone(sn_res)
+
+    def test_skip(self):
+        skipped = self._tests.skip(5).to_list()
+
+        self.assertEqual(len(skipped), len(self._tests) - 5)
+        self.assertEqual(skipped, self._tests.to_list()[5:])
+
+    def test_skip_last(self):
+        skipped = self._tests.skip_last(5)
+
+        self.assertEqual(skipped.count(), len(self._tests) - 5)
+        self.assertEqual(skipped.to_list(), self._tests.to_list()[:-5])
+        self.assertEqual(skipped.last(), self._tests.to_list()[:-5][len(self._tests.to_list()[:-5]) - 1])
+
+    def test_sum(self):
+        res = self._tests.sum(lambda u: u.address.nr)
+
+        s_res = 0
+        for user in self._tests:
+            s_res += user.address.nr
+
+        self.assertEqual(s_res, res)
+
+        tests = Enumerable(values=list(range(0, 100)))
+        self.assertEqual(0, tests.min())
+
+        def invalid():
+            tests2 = Enumerable(str, ['hello', 'world'])
+            e_res = tests2.average()
+
+        self.assertRaises(InvalidTypeException, invalid)
+
+    def test_take(self):
+        skipped = self._tests.take(5)
+
+        self.assertEqual(skipped.count(), 5)
+        self.assertEqual(skipped.to_list(), self._tests.to_list()[:5])
+
+    def test_take_last(self):
+        skipped = self._tests.take_last(5)
+
+        self.assertEqual(skipped.count(), 5)
+        self.assertEqual(skipped.to_list(), self._tests.to_list()[-5:])
+        self.assertEqual(skipped.last(), self._tests.to_list()[len(self._tests) - 1])
+
+    def test_where(self):
+        results = []
+        for user in self._tests:
+            if user.address.nr == 5:
+                results.append(user)
+
+        res = self._tests.where(lambda u: u.address.nr == 5)
+        self.assertEqual(len(results), len(res))
+
+        def ex():
+            e_res = self._tests.where(None)
+
+        self.assertRaises(ArgumentNoneException, ex)

unittests/unittests_query/enumerable_test_case.py

@@ -1,13 +1,12 @@
 import unittest
 
-from cpl_query.extension.lazy_list import LazyList
+from cpl_query.enumerable.enumerable import Enumerable
-from cpl_query.extension.list import List
 
 
 class EnumerableTestCase(unittest.TestCase):
 
     def setUp(self) -> None:
-        self._list = LazyList(int)
+        self._list = Enumerable(int)
 
     def _clear(self):
         self._list.clear()
@@ -22,19 +21,19 @@ class EnumerableTestCase(unittest.TestCase):
         self.assertRaises(Exception, lambda v: self._list.add(v), '3')
 
     def test_default(self):
-        self.assertEqual(LazyList.empty().to_list(), [])
+        self.assertEqual(Enumerable.empty().to_list(), [])
-        self.assertEqual(LazyList.range(0, 100).to_list(), list(range(0, 100)))
+        self.assertEqual(Enumerable.range(0, 100).to_list(), list(range(0, 100)))
 
     def test_iter(self):
         n = 0
-        elements = LazyList.range(0, 100)
+        elements = Enumerable.range(0, 100)
         while n < 100:
             self.assertEqual(elements.next(), n)
             n += 1
 
     def test_for(self):
         n = 0
-        for i in LazyList.range(0, 100):
+        for i in Enumerable.range(0, 100):
             self.assertEqual(i, n)
             n += 1
 
@@ -43,7 +42,7 @@ class EnumerableTestCase(unittest.TestCase):
         self._list.add(2)
         self._list.add(3)
 
-        self.assertEqual(self._list[2], [1, 2, 3][2])
+        self.assertEqual(self._list.element_at(2), [1, 2, 3][2])
 
     def test_count(self):
         self._list.add(1)

unittests/unittests_query/iterable_query_test_case.py

@@ -8,7 +8,7 @@ from cpl_query.extension.list import List
 from unittests_query.models import User, Address
 
 
-class QueryTestCase(unittest.TestCase):
+class IterableQueryTestCase(unittest.TestCase):
 
     def setUp(self) -> None:
         self._tests = List(User)
@@ -19,6 +19,13 @@ class QueryTestCase(unittest.TestCase):
                 15
             )
         )
+        self._t_user2 = User(
+            'Test user',
+            Address(
+                'teststr.',
+                14
+            )
+        )
 
         self._generate_test_data()
 
@@ -35,6 +42,7 @@ class QueryTestCase(unittest.TestCase):
             self._tests.append(user)
 
         self._tests.append(self._t_user)
+        self._tests.append(self._t_user2)
 
     def test_any(self):
         results = []
@@ -169,7 +177,7 @@ class QueryTestCase(unittest.TestCase):
 
     def test_max(self):
         res = self._tests.max(lambda u: u.address.nr)
-        self.assertEqual(self._t_user.address.nr, res)
+        self.assertEqual(res, self._t_user.address.nr)
 
         tests = List(values=list(range(0, 100)))
         self.assertEqual(99, tests.max())
@@ -195,40 +203,41 @@ class QueryTestCase(unittest.TestCase):
 
     def test_order_by(self):
         res = self._tests.order_by(lambda user: user.address.street)
-        res2 = self._tests.order_by(lambda user: user.address.nr)
+        res2 = self._tests.order_by(lambda user: user.address.nr).to_list()
-        s_res = self._tests
+        s_res = self._tests.to_list()
         s_res.sort(key=lambda user: user.address.street)
+        self.assertEqual(res.to_list(), s_res)
 
-        self.assertEqual(res, s_res)
+        s_res = self._tests.to_list()
         s_res.sort(key=lambda user: user.address.nr)
         self.assertEqual(res2, s_res)
 
         self.assertEqual(self._t_user, res.where(lambda u: u.address.nr == self._t_user.address.nr).single())
 
     def test_order_by_descending(self):
-        res = self._tests.order_by_descending(lambda user: user.address.street)
+        res = self._tests.order_by_descending(lambda user: user.address.street).to_list()
-        res2 = self._tests.order_by_descending(lambda user: user.address.nr)
+        res2 = self._tests.order_by_descending(lambda user: user.address.nr).to_list()
-        s_res = self._tests
+        s_res = self._tests.to_list()
         s_res.sort(key=lambda user: user.address.street, reverse=True)
 
         self.assertEqual(res, s_res)
+        s_res = self._tests.to_list()
         s_res.sort(key=lambda user: user.address.nr, reverse=True)
         self.assertEqual(res2, s_res)
 
     def test_then_by(self):
-        res = self._tests.order_by(lambda user: user.address.street[0]).then_by(lambda user: user.address.nr)
+        res = self._tests.order_by(lambda user: user.address.street).then_by(lambda user: user.address.nr).to_list()
 
-        s_res = self._tests
+        s_res = self._tests.to_list()
-        s_res.sort(key=lambda user: (user.address.street[0], user.address.nr))
+        s_res.sort(key=lambda user: (user.address.street, user.address.nr))
 
         self.assertEqual(res, s_res)
 
     def test_then_by_descending(self):
-        res = self._tests.order_by_descending(lambda user: user.address.street[0]).then_by_descending(
+        res = self._tests.order_by_descending(lambda user: user.address.street).then_by_descending(lambda user: user.address.nr).to_list()
-            lambda user: user.address.nr)
 
-        s_res = self._tests
+        s_res = self._tests.to_list()
-        s_res.sort(key=lambda user: (user.address.street[0], user.address.nr), reverse=True)
+        s_res.sort(key=lambda user: (user.address.street, user.address.nr), reverse=True)
 
         self.assertEqual(res, s_res)
 
@@ -237,7 +246,7 @@ class QueryTestCase(unittest.TestCase):
         l_res = self._tests.to_list()
         l_res.reverse()
 
-        self.assertEqual(l_res, res)
+        self.assertEqual(res.to_list(), l_res)
 
     def test_select(self):
         range_list = List(int, range(0, 100))
@@ -251,10 +260,10 @@ class QueryTestCase(unittest.TestCase):
         self.assertEqual(range_list.where(lambda x: x % 2 == 0).to_list(), modulo_range)
 
     def test_select_many(self):
-        range_list = List(int, range(0, 100))
+        range_list = List(int, list(range(0, 100)))
         selected_range = range_list.select(lambda x: [x, x])
 
-        self.assertEqual(selected_range, [[x, x] for x in range(0, 100)])
+        self.assertEqual(selected_range.to_list(), [[x, x] for x in range(0, 100)])
         self.assertEqual(selected_range.select_many(lambda x: x).to_list(), [_x for _l in [2 * [x] for x in range(0, 100)] for _x in _l])
 
         class TestClass:
@@ -285,17 +294,17 @@ class QueryTestCase(unittest.TestCase):
         self.assertIsNone(sn_res)
 
     def test_skip(self):
-        skipped = self._tests.skip(5)
+        skipped = self._tests.skip(5).to_list()
 
-        self.assertEqual(len(self._tests) - 5, len(skipped))
+        self.assertEqual(len(skipped), len(self._tests) - 5)
-        self.assertEqual(self._tests[5:], skipped)
+        self.assertEqual(skipped, self._tests[5:])
 
     def test_skip_last(self):
         skipped = self._tests.skip_last(5)
 
-        self.assertEqual(len(self._tests) - 5, len(skipped))
+        self.assertEqual(skipped.count(), len(self._tests) - 5)
-        self.assertEqual(self._tests[:-5], skipped)
+        self.assertEqual(skipped.to_list(), self._tests[:-5])
-        self.assertEqual(self._tests[:-5][len(self._tests[:-5]) - 1], skipped.last())
+        self.assertEqual(skipped.last(), self._tests[:-5][len(self._tests[:-5]) - 1])
 
     def test_sum(self):
         res = self._tests.sum(lambda u: u.address.nr)
@@ -318,15 +327,15 @@ class QueryTestCase(unittest.TestCase):
     def test_take(self):
         skipped = self._tests.take(5)
 
-        self.assertEqual(5, len(skipped))
+        self.assertEqual(skipped.count(), 5)
-        self.assertEqual(self._tests[:5], skipped)
+        self.assertEqual(skipped.to_list(), self._tests[:5])
 
     def test_take_last(self):
         skipped = self._tests.take_last(5)
 
-        self.assertEqual(5, len(skipped))
+        self.assertEqual(skipped.count(), 5)
-        self.assertEqual(self._tests[-5:], skipped)
+        self.assertEqual(skipped.to_list(), self._tests[-5:])
-        self.assertEqual(self._tests[len(self._tests) - 1], skipped.last())
+        self.assertEqual(skipped.last(), self._tests[len(self._tests) - 1])
 
     def test_where(self):
         results = []

unittests/unittests_query/iterable_test_case.py

@@ -17,5 +17,5 @@ class IterableTestCase(unittest.TestCase):
         self._list.append(2)
         self._list.append(3)
 
-        self.assertEqual(self._list, [1, 2, 3])
+        self.assertEqual(self._list.to_list(), [1, 2, 3])
         self.assertRaises(Exception, lambda v: self._list.append(v), '3')

unittests/unittests_query/query_test_suite.py

@@ -1,8 +1,9 @@
 import unittest
 
+from unittests_query.enumerable_query_test_case import EnumerableQueryTestCase
 from unittests_query.enumerable_test_case import EnumerableTestCase
+from unittests_query.iterable_query_test_case import IterableQueryTestCase
 from unittests_query.iterable_test_case import IterableTestCase
-from unittests_query.query_test_case import QueryTestCase
 
 
 class QueryTestSuite(unittest.TestSuite):
@@ -11,9 +12,10 @@ class QueryTestSuite(unittest.TestSuite):
         unittest.TestSuite.__init__(self)
 
         loader = unittest.TestLoader()
-        self.addTests(loader.loadTestsFromTestCase(QueryTestCase))
         self.addTests(loader.loadTestsFromTestCase(EnumerableTestCase))
+        self.addTests(loader.loadTestsFromTestCase(EnumerableQueryTestCase))
         self.addTests(loader.loadTestsFromTestCase(IterableTestCase))
+        self.addTests(loader.loadTestsFromTestCase(IterableQueryTestCase))
 
     def run(self, *args):
         super().run(*args)