Improved avg query

src/cpl_query/extension/iterable_abc.py

@@ -5,17 +5,35 @@ from typing import Optional, Callable, Union
 class IterableABC(ABC, list):
 
     @abstractmethod
-    def __init__(self):
+    def __init__(self, t: type = None, values: list = None):
         list.__init__(self)
 
+        if t == any:
+            t = None
+        self._type = t
+
+        if values is not None:
+            for value in values:
+                self.append(value)
+
+    @property
+    def type(self) -> type:
+        return self._type
+
     @abstractmethod
     def any(self, func: Callable) -> bool: pass
 
     @abstractmethod
     def all(self, func: Callable) -> bool: pass
 
+    def append(self, __object: object) -> None:
+        if self._type is not None and type(__object) != self._type and not isinstance(type(__object), self._type):
+            raise Exception(f'Unexpected type: {type(__object)}')
+
+        super().append(__object)
+
     @abstractmethod
-    def average(self, t: type, func: Callable) -> Union[int, float, complex]: pass
+    def average(self, func: Callable = None) -> Union[int, float, complex]: pass
 
     @abstractmethod
     def contains(self, value: object) -> bool: pass

src/cpl_query/extension/list.py

@@ -4,15 +4,4 @@ from .._extension.iterable import Iterable
 class List(Iterable):
 
     def __init__(self, t: type = None, values: list = None):
-        Iterable.__init__(self)
-
-        self._type = t
-
-        if values is not None:
-            self.extend(values)
-
-    def append(self, __object: object) -> None:
-        if self._type is not None and type(__object) != self._type and not isinstance(type(__object), self._type):
-            raise Exception(f'Unexpected type: {type(__object)}')
-
-        super().append(__object)
+        Iterable.__init__(self, t, values)