python--字典

>>> d={'a':1,'b':2}
>>> for x in d.values():
...     print (x)
...
1
2

>>> d={'a':1,'b':2}
>>> for k,v in d.items():
...     print (k)
...
b
a

>>> d={'a':1,'b':2}
>>> b=d.pop('a')
>>> b
1
>>> d
{'b': 2}

>>> e=d.pop('f')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: 'f'

>>> e=d.pop('f',None)
>>>