python中删除字典的指定键值对

1、

>>> a = {"a":111,"b":222,"c":333,"d":444}
>>> a
{'a': 111, 'b': 222, 'c': 333, 'd': 444}
>>> del a["a"]
>>> a
{'b': 222, 'c': 333, 'd': 444}
>>> del a["c"]
>>> a
{'b': 222, 'd': 444}

2、

>>> a = dict( a = 111, b = 222, c = 333, d = 444)
>>> a
{'a': 111, 'b': 222, 'c': 333, 'd': 444}
>>> a.pop("a")
111
>>> a
{'b': 222, 'c': 333, 'd': 444}
>>> a.pop("c")
333
>>> a
{'b': 222, 'd': 444}

3、

>>> a = dict(a = 111, b = 222, c = 333, d = 444)
>>> a
{'a': 111, 'b': 222, 'c': 333, 'd': 444}
>>> a.popitem()
('d', 444)
>>> a
{'a': 111, 'b': 222, 'c': 333}
>>> a.popitem()
('c', 333)
>>> a
{'a': 111, 'b': 222}