• 数据类型


    数据类型概述

    int 整型

    float 浮点型

    bool 布尔

    string 字符串 -不可变

    dict 字典 -可变类型

    list 列表 [] -可变

    tuple 元组 () -不可变类型

    set 集合 {} -可变类型

    字符串

    举例说明

    name="alex   
     	"
    print(name.strip())
    '''
    alex
    '''
    1. 移除空白 strip
    bb="alex|egon|qiqi|huihui"
    print(bb.split("|"))
    '''
    ['alex', 'egon', 'qiqi', 'huihui'] #列表
    '''
    2. 切分 split
    bb="alexegonqiqihuihui"
    print("|".join(bb))
    '''
    a|l|e|x|e|g|o|n|q|i|q|i|h|u|i|h|u|i
    '''
    3. 组合join
    aa="alex"
    print(aa.index("a")) #没有就会报错
    print(aa.find("a")) #没有显示-1
    print(aa[0])
    '''
    0
    0
    a
    '''
    4. 按照索引正反取值 index find
    aa="alex"
    print(len(aa))
    5. 长度 len
    aa="qiqihuihui"
    
    print(aa[0:4])
    print(aa[0:-1])
    '''
    qiqi
    qiqihuihu
    '''
    6. 切片 (顾头不顾尾)
    aa="qiqiHUIhui"
    print(aa.upper())
    print(aa.lower())
    '''
    QIQIHUIHUI
    qiqihuihui
    '''
    7. 大小写转换 lower upper
    aa="qiqiHUIhui"
    if "qiqi" in aa:
        print(True)
    else:
        print(False)
    8. in和not in 成员运算
    aa="qiqi"
    for i in aa:
        print(i)
    9. 循环for
    aa="qiqi"
    print(aa.startswith("q"))
    print(aa.endswith("i"))
    10. 判断开始结束元素 startswith、endswith
    aa="qiqi"
    bb=aa.replace("qiqi","gege")
    print(bb)
    print(aa)
    11. 替换 replace
    age="18"
    print(age.isdigit())
    '''
    True
    '''
    12. 是否是数字 isdigit
    13. 格式化输出  format三种方式
    13. 格式化输出 format三种方式

     字典

    举例说明

    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    
    print(dic["name"])
    print(dic.get("name"))
    '''
    alex
    alex
    '''
    1. 根据key取值 可取可存
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    
    
    print(len(dic)) #3
    2. 长度 len
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    
    if "alex" in dic.get("name"):
        print(True) #True
    3. 成员判断 in和not in
    #1. pop
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    dic.pop("name")
    print(dic)
    '''
    {'age': 13, 'hobby': 'gril'}
    '''
    
    #2. popitem 随机删除一个键值对
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    v=dic.popitem()
    print(v)
    print(dic)
    '''
    ('hobby', 'gril')
    {'name': 'alex', 'age': 13}
    '''
    
    #3. del
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    del dic["name"]
    print(dic)
    '''
    {'age': 13, 'hobby': 'gril'}
    '''
    4. 删除
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    
    dic.setdefault("job","teacher")
    print(dic)
    '''
    {'name': 'alex', 'age': 13, 'hobby': 'gril', 'job': 'teacher'}
    '''
    5. setdefault 存在不做处理,不存在增加
    #keys() values() items()
    
    dic={
        "name":"alex",
        "age":13,
        "hobby":"gril"
    }
    
    for k in dic.keys():
        print(k)
    '''
    name
    age
    hobby
    '''
    
    for  v in dic.values():
        print(v)
    '''
    alex
    13
    gril
    '''
    
    for k,v in dic.items():
        print(k,v)
    '''
    name alex
    age 13
    hobby gril
    '''
    6. 循环

    列表

    lists=["alex","egon","qiqi",1,2,3]
    print(lists.index("alex"))
    print(lists[0])
    '''
    0
    alex
    '''
    1. 按照索引正反取值 index
    lists=["alex","egon","qiqi",1,2,3]
    print(len(lists))
    2. 长度 len
    lists=["alex","egon","qiqi",1,2,3]
    print(lists[0:3])
    '''
    ['alex', 'egon', 'qiqi']
    '''
    3. 切片
    lists=["alex","egon","qiqi",1,2,3]
    
    if "alex" in lists:
        print(True)
    4. 成员判断 in 和not in
    lists=["alex","egon","qiqi",1,2,3]
    
    lists.append("新加")
    print(lists)
    '''
    ['alex', 'egon', 'qiqi', 1, 2, 3, '新加']
    '''
    5. 追加 append
    #1. pop 弹出
    lists=["alex","egon","qiqi",1,2,3]
    pop_obj=lists.pop(0)
    print(pop_obj)
    print(lists)
    '''
    alex
    ['egon', 'qiqi', 1, 2, 3]
    '''
    #2. remove
    lists=["alex","egon","qiqi",1,2,3]
    lists.remove("alex")
    print(lists)
    '''
    ['egon', 'qiqi', 1, 2, 3]
    '''
    #3. del
    lists=["alex","egon","qiqi",1,2,3]
    del lists[0]
    print(lists)
    6. 删除
    lists=["alex","egon","qiqi",1,2,3]
    
    for i in lists:
        print(i)
    '''
    alex
    egon
    qiqi
    1
    2
    3
    '''
    7. 循环

    元组

    参考列表的用法

    1. 按照索引取值 只能取
    2. 切片
    3. 长度 len
    4. 成员判断 in 和 not in
    5. 循环

    集合

    1. 长度 len

    2. 成员判断 in 和not in

    group1={"alex","egon","qiqi","binbin"}
    group1.add("xinjia")
    print(group1)
    '''
    {'binbin', 'egon', 'alex', 'xinjia', 'qiqi'}
    '''
    3. 添加 无则添加,有则不操作
    #1. pop 随机删除
    group1={"alex","egon","qiqi","binbin"}
    group1.pop() #随机删除
    print(group1)
    '''
    {'binbin', 'qiqi', 'alex'}
    '''
    #2. discard
    group1={"alex","egon","qiqi","binbin"}
    group1.discard("binbin") 
    print(group1)
    '''
    {'qiqi', 'alex', 'egon'}
    '''
    #3. remove
    group1={"alex","egon","qiqi","binbin"}
    
    group1.remove("binbin") 
    print(group1)
    '''
    {'egon', 'qiqi', 'alex'}
    '''
    4. 删除
    #1. difference 输出 se1中有的,se2中无的 赋值给新的变量
    se1 = {'alex','eric','qiqi','dh'}
    se2 = {'alex','eric','gege','yiyi'}
    v = se1.difference(se2)
    print(v)#{'qiqi', 'dh'}
    #2. difference_update 输出 将se1中有的,se2中无的 重新赋值给se1 (se1会被清空,变成se1中有的,se2中无的值)
    se1 = {'alex','eric','qiqi','dh'}
    se2 = {'alex','eric','gege','yiyi'}
    se1.difference_update(se2)
    print(se1) #{'qiqi', 'dh'}
    #3. symmetric_difference 将两者不同的 赋值给新的变量
    se1 = {'alex','eric','qiqi','dh'}
    se2 = {'alex','eric','gege','yiyi'}
    v = se1.symmetric_difference(se2)
    se1.symmetric_difference_update(se2)#将两者不同的 覆盖赋值给se1
    print(se1)
    print(v)
    '''
    {'dh', 'qiqi', 'gege', 'yiyi'}
    {'dh', 'qiqi', 'gege', 'yiyi'}
    
    '''
    5. 差集
    se1 = {'alex','eric','qiqi','dh'}
    se2 = {'alex','eric','gege','yiyi'}
    v = se1.intersection(se2)
    se1.intersection_update(se2) #将交集覆盖赋值给se1
    print(se1)
    print(v)
    6. 交集
    se1 = {'alex','eric','qiqi','dh'}
    se2 = {'alex','eric','gege','yiyi'}
    v = se1.union(se2)
    print(v)
    7. 并集
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  • 原文地址:https://www.cnblogs.com/lazyball/p/11646628.html
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