python 有效的Python项目23 classの特殊メソッド__call__のサンプル：リスト内の偶数を数える

Posted 2021-05-09

class Counter():
    def __init__(self):
        self.i = 0

    def __call__(self):
        self.i += 1
        return 0


def foo(func, a):
    for i in a:
        if i % 2 == 0:
            func()
    return sorted(a)


c = Counter()
a = [1, 3, 5, 7, 8, 9]
print(foo(c, a))
print(c.i)