for i in d: d = d.remove(i) return int(x) 测试时,它在第15行(以斜体显示)返回以下错误: File "/Users/ob/untitled0.py", line 15, in ma
AttributeError: 'NoneType' objecthas no attribute 'remove
在Python中有None单例,它在某些情况下表现得相当奇怪:>>> type(a)>>> isinstance(a,None)TypeError: isinstance() arg 2 must be a class, type, or tuple of classes and types
首先,<type 'NoneType'>显示