在python中 None, False, 空字符串"", 0, 空列表[], 空字典{}, 空元組()都相當於False ,即:
not None == not False == not '' == not 0 == not [] == not {} == not ()
not = !
在python中 None, False, 空字符串"", 0, 空列表[], 空字典{}, 空元組()都相當於False ,即:
not None == not False == not '' == not 0 == not [] == not {} == not ()
not = !
https://stackoverflow.com/questions/419163/what-does-if-name-main-do