python数据结构之字典

深碍√TFBOYSˉ_ 2024-02-18 23:55 87阅读 0赞

#!/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