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  • 列表、元组、字典

    列表
    def append(self, p_object):

        '''在列表末尾添加一个元素'''
    l2 = [20,40,70,100]
    l2.append(1)
    l2.append(2)
    l2.append(3)
    print(l2)

    [20, 40, 70, 100, 1, 2, 3]

    def count(self, value):

        '''总计一个元素在列表中出现的次数'''
    l2 = [20,40,70,100,20,70,80,20]
    print(l2.count(20))
    3

    def extend(self, iterable):

        '''向列表里添加多个元素或另一个列表'''
    #1
    l1 = [2,4,7,10]
    l2 = [20,40,70,100,20,70,80,20]
    l2.extend(l1)
    print(l2)
    [20, 40, 70, 100, 20, 70, 80, 20, 2, 4, 7, 10]
    #2
    l2 = [20,40,70,100,20,70,80,20]
    l2.extend('qwer')
    print(l2)

    [20, 40, 70, 100, 20, 70, 80, 20, 'q', 'w', 'e', 'r']

    def index(self, value, start=None, stop=None):

          '''返回列表中某个元素第一次出现时的索引值'''
    l2 = [20,40,70,100,20,70,80,20]
    print(l2.index(100))

    3

    def insert(self, index, p_object):

          '''向列表中插入一个元素,可以指定插入位置'''
    l2 = [20,40,70,100,20,70,80,20]
    l2.insert(0,100)
    print(l2)

    [100, 20, 40, 70, 100, 20, 70, 80, 20]

    def pop(self, index=None):

          '''删除列表中最后一个元素'''
    l2 = [20,40,70,100,20,70,80,20]
    print(l2.pop())
    print(l2)
    20
    [20, 40, 70, 100, 20, 70, 80]

    def remove(self, value):

          '''从开头开始查找删除匹配到的第一个元素'''
    l2 = [20,40,70,100,20,70,80,20]
    l2.remove(20)
    print(l2)

    [40, 70, 100, 20, 70, 80, 20]

    def reverse(self):

          '''把列表倒过来'''
    l2 = [20,40,70,100,20,70,80,20]
    l2.reverse()
    print(l2)

    [20, 80, 70, 20, 100, 70, 40, 20]

    def sort(self, cmp=None, key=None, reverse=False):
          '''列表排序,默认按从小到大排序'''
    l2 = [20,40,70,100,20,70,80,20]
    l2.sort()
    print(l2)
    [20, 20, 20, 40, 70, 70, 80, 100]

    元组

    def count(self, value):
        '''统计元组中元素出现的次数'''
    tu = (1,2,3,4,5,11,22,33,44,55,66,1,2,3,4,5,6,1)
    print(tu.count(1))

    3

    def index(self, value, start=None, stop=None):
        '''显示元组中指定元素第一次出现的索引'''
    tu = (1,2,3,4,5,11,22,33,44,55,66,1,2,3,4,5,6,1)
    print(tu.index(5))
    4

    字典

    def clear(self):
        '''清除字典里所有元素'''
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic.clear()
    print(dic)
    {1: '大唐', 2: 'st', 3: 'fc'}
    {}

    def copy(self):

        '''复制字典'''
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.copy()
    print(dic2)
    {1: '大唐', 2: 'st', 3: 'fc'}
    {1: '大唐', 2: 'st', 3: 'fc'}

    def get(self, k, d=None):
        '''根据key得到对应的值'''
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.get(2)
    print(dic2)


    {1: '大唐', 2: 'st', 3: 'fc'}
    st

    def items(self):
        """ 所有项的列表形式 """
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.items()
    print(dic2)

    {1: '大唐', 2: 'st', 3: 'fc'}
    dict_items([(1, '大唐'), (2, 'st'), (3, 'fc')])

    def keys(self):
          """ 字典所有的key列表 """
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.keys()
    print(dic2)

    {1: '大唐', 2: 'st', 3: 'fc'}
    dict_keys([1, 2, 3])

    def pop(self, k, d=None):

          '''获取并移除字典中一对元素'''
    dic = {
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.pop(2)
    print(dic2)
    print(dic)

    {1: '大唐', 2: 'st', 3: 'fc'}
    st
    {1: '大唐', 3: 'fc'}

    def popitem(self):

          '''获取并一处字典中第一对元素'''
    dic = {
    0:'长安',
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.popitem()
    print(dic2)
    print(dic)
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc'}
    (0, '长安')
    {1: '大唐', 2: 'st', 3: 'fc'}

    def setdefault(self, k, d=None):

            '''如果key不存在,则创建,如果存在,则返回已存在的值且不修改'''
    dic = {
    0:'长安',
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.setdefault(4)
    print(dic2)
    print(dic)

    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc'}
    None
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc', 4: None}

    def update(self, E=None, **F):

            '''更新,可以将一个字典追加到另一个字典里面'''  
    dic = {
    0:'长安',
    1:'大唐',
    2:'st',
    3:'fc'
    }
    dic1 = {
    'A':'飞燕女',
    'B':'逍遥生',
    'C':'玄彩娥'
    }
    print(dic)
    dic2 = dic.update(dic1)
    print(dic2)
    print(dic)
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc'}
    None
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc', 'B': '逍遥生', 'C': '玄彩娥', 'A': '飞燕女'}

    def values(self):

         '''列出字典中所有值'''
    dic = {
    0:'长安',
    1:'大唐',
    2:'st',
    3:'fc'
    }
    print(dic)
    dic2 = dic.values()
    print(dic2)
    print(dic
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc'}
    dict_values(['长安', '大唐', 'st', 'fc'])
    {0: '长安', 1: '大唐', 2: 'st', 3: 'fc'}

          

        
     


     


     
     
    
    

      
     
     
     
     
     

      

          
     














     
     
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  • 原文地址:https://www.cnblogs.com/xianyin/p/5640011.html
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