python xx003字典

将2个列表根据元素位置合并成字典：

方法一：

>>> a
['shanghai', 'chengdu', 'shandong']
>>> b
['wo', 'chun', 'bing']
>>> c = dict(zip(a,b))
>>> c
{'shanghai': 'wo', 'chengdu': 'chun', 'shandong': 'bing'}
>>> c['shandong']
'bing'

取2个列表同样位置的元素：

>>> a
['shanghai', 'chengdu', 'shandong']
>>> b
['wo', 'chun', 'bing']
>>> b[a.index('shandong')]
'bing'
>>> 

创建列表

#方法一
>>> dict1 = dict((('a' ,20), ('b' ,30)))
>>> dict1
{'a': 20, 'b': 30}
#方法二：
>>> dict2 = dict('i'='shandong', 'she'='chengdu')
SyntaxError: keyword can't be an expression
>>> dict2 = dict(i='shandong', she='chengdu')
>>> dict2
{'i': 'shandong', 'she': 'chengdu'}
#列表增加元素
>>> dict2['he'] = 'chongqing'
>>> dict2
{'i': 'shandong', 'she': 'chengdu', 'he': 'chongqing'}