#!/usr/bin/python3
#-*-encoding:utf-8-*-
"""
@project_name = pytest
@file = dict.py
@author = angel
@create_time = 2018/9/24 9:26
"""

print('='*100)
# 手写一个字典
dict1={'myint':1,'myfloat':3.14,'mystr':'qwerty','mytuple':(1,2,3),'nulldict':{}}
print(dict1)
# 空字典
empty_dict={}
print(empty_dict)
# list转换为字典
dict2=dict([('myint',1),('myfloat',3.14),('mystr','name'),('mytuple',(1,2,3)),('mydict',{})])
print(dict2)
# dict函数
a,b,c=0,1,2
dict3=dict(zero=a,one=b,two=c)
print(dict3)
empty_dict2=dict()
print(empty_dict2)
print('='*30)
# 提取元素
mydict3={'spring':(3,4,5),'summer':(6,7,8),'autumn':(9,10,11),'winter':(12,1,2)}
print('spring' in mydict3)
# 用key获取value
'''[]用方括号提取元素'''
print(mydict3['spring'])
'''使用字典方法get'''
print(mydict3.get('winter'))
print(mydict3.get('wasd','字典里没有这个key'))


# 添加字典元素
country=dict(China='beijing',America='wasdingdon',Britain='London')
print(country)
country2=country.copy()       #复制字典
print(country2)
country2['Russian']='Moscow'  #添加字典元素
print(country2)


# 更新字典元素
others=dict(Australia='Canberra',Japan='tokyo',Canada='OTTAWA')
country2.update(others)  #update方法可以合并两个字典
print(country2)
# 修改某个key对应的value
country2['Canada']='Ottawa'

print('='*30)
# 获取所有key
all_keys=country2.keys()
print(all_keys)
print('China' in all_keys)
print(list(all_keys))
# 获取所有value
all_values=country2.values()
print(all_values)
print('beijing' in all_values)
print(list(all_values))  #将所有value用list打印出来

# 用value获取key
keys= list(all_keys)
values=list(all_values)
print(keys[values.index('beijing')])
print('-----------------')

#用items方法获取全部键值对
all_items=country2.items()
print(all_items)
print(('China','beijing') in all_items)
print(list(all_items))  #将所有items用list打印出来

print('-----------------------------------------------')
# 删除字典元素
del country2['Japan']  #使用del语句删除某个键值对
print(country2)
old_value=country2.pop('Canada')  #使用pop方法删除某个键值对,返回被删除的value
print(old_value)
print(country2)
country2.clear()  #clear方法清空字典所有键值对
print(country2)

运行结果

C:\Users\angel\PycharmProjects\pytest\venv\Scripts\python.exe C:/Users/angel/PycharmProjects/pytest/dict.py
====================================================================================================
{'myint': 1, 'myfloat': 3.14, 'mystr': 'qwerty', 'mytuple': (1, 2, 3), 'nulldict': {}}
{}
{'myint': 1, 'myfloat': 3.14, 'mystr': 'name', 'mytuple': (1, 2, 3), 'mydict': {}}
{'zero': 0, 'one': 1, 'two': 2}
{}
==============================
True
(3, 4, 5)
(12, 1, 2)
字典里没有这个key
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London'}
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London'}
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London', 'Russian': 'Moscow'}
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London', 'Russian': 'Moscow', 'Australia': 'Canberra', 'Japan': 'tokyo', 'Canada': 'OTTAWA'}
==============================
dict_keys(['China', 'America', 'Britain', 'Russian', 'Australia', 'Japan', 'Canada'])
True
['China', 'America', 'Britain', 'Russian', 'Australia', 'Japan', 'Canada']
dict_values(['beijing', 'wasdingdon', 'London', 'Moscow', 'Canberra', 'tokyo', 'Ottawa'])
True
['beijing', 'wasdingdon', 'London', 'Moscow', 'Canberra', 'tokyo', 'Ottawa']
China
-----------------
dict_items([('China', 'beijing'), ('America', 'wasdingdon'), ('Britain', 'London'), ('Russian', 'Moscow'), ('Australia', 'Canberra'), ('Japan', 'tokyo'), ('Canada', 'Ottawa')])
True
[('China', 'beijing'), ('America', 'wasdingdon'), ('Britain', 'London'), ('Russian', 'Moscow'), ('Australia', 'Canberra'), ('Japan', 'tokyo'), ('Canada', 'Ottawa')]
-----------------------------------------------
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London', 'Russian': 'Moscow', 'Australia': 'Canberra', 'Canada': 'Ottawa'}
Ottawa
{'China': 'beijing', 'America': 'wasdingdon', 'Britain': 'London', 'Russian': 'Moscow', 'Australia': 'Canberra'}
{}

Process finished with exit code 0