ython遍历字典并修改，错误：dictionary changed size during iteration参考：https://www.python.org/dev/peps/pep-0234/大概是说字典在遍历时不能进行修改，建议转成列表或集合处理。解决：把字典的keys变成list。
a={'a':1, 'b':0, 'c':1, 'd':0} for key in list(a.keys()): del a[key]