Python学习笔记：字典的使用

字典的基本操作
键值查找：>>> ainfo={'Wangdachui':3000,'Niuyun':2000,'Linling':4500,'Tianqi':8000}
>>> ainfo['Niuyun']
2000更新：>>> ainfo['Niuyun']=9999
>>> ainfo
{'Wangdachui': 3000, 'Niuyun': 9999, 'Linling': 4500, 'Tianqi': 8000}添加：>>> ainfo['Fuyun']=1000
>>> ainfo
{'Wangdachui': 3000, 'Niuyun': 9999, 'Linling': 4500, 'Tianqi': 8000, 'Fuyun': 1000}成员判断：>>> 'Mayun' in ainfo
False删除字典成员：>>> del ainfo['Fuyun']
>>> ainfo
{'Wangdachui': 3000, 'Niuyun': 9999, 'Linling': 4500, 'Tianqi': 8000}字典的内建函数>>> names=['Wangdachui','Niuyun','Linling','Tianqi']
>>> salaries=[3000,2000,4500,8000]
>>> ainfo=dict(zip(names,salaries))
>>> ainfo
{'Wangdachui': 3000, 'Niuyun': 2000, 'Linling': 4500, 'Tianqi': 8000}
>>> len(ainfo)
4
>>> hash('Wangdachui')
-967826530
>>> testList=[1,2,3]
>>> hash(testList)
Traceback (most recent call last):
File "<pyshell#16>", line 1, in <module>
hash(testList)
TypeError: unhashable type: 'list'字典方法>>> ainfo={'Wangdachui':3000,'Niuyun':2000,'Linling':4500,'Tianqi':8000}
>>> ainfo.keys()
dict_keys(['Wangdachui', 'Niuyun', 'Linling', 'Tianqi'])
>>> ainfo.values()
dict_values([3000, 2000, 4500, 8000])
>>> ainfo.items()
dict_items([('Wangdachui', 3000), ('Niuyun', 2000), ('Linling', 4500), ('Tianqi', 8000)])
>>> for k,v in ainfo.items():
print(k,v)

Wangdachui 3000
Niuyun 2000
Linling 4500
Tianqi 8000

>>> ainfo={'Wangdachui':3000,'Niuyun':2000,'Linling':4500}
>>> binfo={'Wangdachui':4000,'Niuyun':9999,'Wangzi':6000}
>>> ainfo.update(binfo)
>>> ainfo
{'Wangdachui': 4000, 'Niuyun': 9999, 'Linling': 4500, 'Wangzi': 6000}

>>> stock={'AXP':78.51,'BA':184.76}
>>> print(stock.get('AAA'))
None
>>> print(stock.get('BA'))
184.76

删除字典：>>> aStock={'AXP':78.51,'BA':184.76}
>>> bStock=aStock
>>> aStock={}
>>> bStock
{'AXP': 78.51, 'BA': 184.76}

>>> aStock={'AXP':78.51,'BA':184.76}
>>> bStock=aStock
>>> aStock.clear()
>>> aStock
{}
>>> bStock
{}

字典相关使用小案例>>> x={'name':'Niuyun','address':{'city':'Beijing','Street':'Chaoyang Road'}}
>>> x['address']['Street']
'Chaoyang Road'

>>> import requests
>>> kw={'q':'Python dict'}
>>> r=requests.get('http://cn.bing.com/search',params=kw)
>>> r.url
'http://cn.bing.com/search?q=Python+dict'
>>> print(r.text)

可变长关键字参数（字典）：>>> def func(args1,*argst,**argsd):
print(args1)
print(argst)
print(argsd)

>>> func('Hello','Wangdachui','Niuyun','Linling',a1=1,a2=2,a3=3)
Hello
('Wangdachui', 'Niuyun', 'Linling')
{'a1': 1, 'a2': 2, 'a3': 3}