是否有关于此函数(在 python3 中)返回 True 的参数？
def p(a,b):
return (a in b and b in a)
请您参考如下方法:
是的，一对相互包含的列表:
a, b = [], []
a.append(b)
b.append(a)
print(a in b and b in a)
或者，一个包含自身的列表:
a = b = []
a.append(a)
print(a in b and b in a)
或者，破解 __contains__，in 运算符调用:
class Foo:
def __contains__(self, other):
return True
a = Foo()
b = Foo()
print(a in b and b in a)
或者，相等的字符串:
a = 'foo'
b = 'foo'
print(a in b and b in a)
或者，相互产生的生成器:
def foo():
x = yield
while True:
yield x
a = foo()
b = foo()
next(a)
next(b)
a.send(b)
b.send(a)
print(a in b and b in a)
这是个笑话，它永远不会结束:
import math
from itertools import count
a = math.inf
b = count()
print(a in b and b in a)
