python常用抽象基类1

 

 

from abc import abstractmethod
from collections.abc import Container, Sized, Iterable, Iterator
from collections.abc import Sequence, Mapping, Set
from collections.abc import MutableSequence, MutableMapping, MutableSet
from collections.abc import MappingView, ItemsView, KeysView, ValuesView
from collections.abc import Callable, Hashable


class UserContainer(Container, Sized, Iterable):

    # 对应len()方法
    def __len__(self) -> int:
        return len(self.items)

    # 对应in关键字
    def __contains__(self, x: object) -> bool:
        return x in self.items

    def __init__(self):
        self.items = list()
        self.index = 0

    def append(self, obj):
        self.items.append(obj)

    # 和__iter__一起实现for in语法
    def __next__(self):
        if self.index < len(self.items):
            v = self.items[self.index]
            self.index += 1
            return v
        else:
            raise StopIteration

    def __iter__(self):
        return self


# Sequence是Container, Sized, Iterable子类
class UserList(Sequence):

    def __init__(self):
        self.data = list()
        self.data.append(1)
        self.data.append(2)

    def __len__(self) -> int:
        return len(self.data)

    # 实现分片取数[]能力
    def __getitem__(self, i: int):
        return self.data[i]


class UserMap(Mapping):
    def __init__(self):
        self.data = dict()
        self.index = 0
        self.data['a'] = 1
        self.data['b'] = 2

    def __len__(self) -> int:
        return len(self.data)

    def __iter__(self):
        return self

    # 实现v=data[k]取数语法
    def __getitem__(self, k):
        return self.data[k]

    # 实现data[k]=赋值语法
    def __setitem__(self, key, value):
        self.data[key] = value


class UserSet(Set):

    def __init__(self):
        self.data = set()
        self.data.add(6)
        self.data.add(7)

    def __contains__(self, x: object) -> bool:
        return x in self.data

    def __len__(self) -> int:
        return len(self.data)

    def __iter__(self):
        return self


if __name__ == '__main__':
    u = UserContainer()
    u.append("u1")
    u.append("u2")
    u.append("u3")
    print("u1" in u)
    print(len(u))
    print("========")
    for i in u:
        print(i)
    print("========")

    u3 = UserList()
    print(u3[1])
    print("************")
    for i in u3:
        print(i)
    print("************")

    u4 = UserMap()
    u4['c'] = 3
    print(u4['a'])

    u5 = UserSet()
    print(9 in u5)