Python中的高阶函数 - ZhangMaozheng/Python GitHub Wiki
>>> abs = len
>>> abs(-6)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: object of type 'int' has no len()
>>> abs('love')
4
>>> abs = len
>>> abs(-6)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: object of type 'int' has no len()
>>> abs('love')
4