派生内置不可变类型并修改其实例化行为
class IntTuple(tuple):
def __new__(cls, iterable):
g = (x for x in iterable if isinstance(x, int) and x > 0)
return super(IntTuple, cls).__new__(cls, g)
def __init__(self, iterable):
# before
# print(self) (1, 6, 3)
super(IntTuple, self).__init__()
# after
t = IntTuple([1, -1, 'abc', 6, ['x', 'y'], 3])
print(t)
'''
1. 判断一个变量是否是int类型：isinstance(x, int)
2. tuple生成器：g = (x for x in iterable if isinstance(x, int) and x > 0)
'''
网友评论