exam = { 'math': '95', 'eng': '96', 'chn': '90', 'phy': '', 'chem': '' }
使用下列遍历的方法删除:
for e in exam: if exam[e] == '': del exam[e]
结果出现下列错误,怎么解决:
Traceback (most recent call last): File "Untitled.py", line 3, in <module> for e in exam:RuntimeError: dictionary changed size during iteration