• 菜鸟python---小数据池


    == is id

    == 判断两个值是否相等

    a = 10
    b = 10
    print(a == b)



    lst = [1,2,3,4]
    lst1 = [1,2,3,4]
    print(lst == lst1)

    is -- 是

    a = 10
    b = 10
    print(a is b)

    代码块:一个py文件,一个函数,一个模块,终端中每一行都是代码块
    int,str,bool

    int:-5 ~ 正无穷
    a = -6
    b = -6
    print(a is b)

    a = 1000
    b = 1000
    print(id(a),id(b))
    print(a is b)

    str:
    字符串:
    1.定义字符串的时候可以是任意的
    2.字符串(字母,数字)进行乘法时总长度不超过20
    3.特殊符号(中文,符号)进行乘法的时候乘以 0 或 1

    a = "asdfasdfa22143df21af啊发生的vuwqtavuiqf!54人24215124"
    b = "asdfasdfa22143df21af啊发生的vuwqtavuiqf!54人24215124"
    print(a == b)
    print(a is b)

    a = "alee" * 6
    b = "alexe" * 6
    print(a == b)
    print(a is b)

    a = "你好啊" * 1
    b = "你好啊" * 1
    print(a == b)
    print(a is b)

    bool:
    True,False

    is 判断的是两边的内存地址是否相同

    小数据池,代码块同在的情况下先执行代码块

    小数据池 -- int,str,bool
    int:-5 ~ 256
    a = 1000
    b = 1000
    print(a is b)

    str:
    1.字母,数字长度任意符合驻留机制
    2.字符串进行乘法的时候总长度不能超过20
    3.特殊符号进行乘法的时候只能乘 0

    a = "asdfasdfasdfsad12341123123121wef214afsda"
    b = "asdfasdfasdfsad12341123123121wef214afsda"
    print(a is b)

    a = "你好啊" * 0
    b = "你好啊" * 0
    print(a is b)

    驻留机制: 节省内存空间,提升效率(减少了开辟空间和销毁空间的耗时)
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  • 原文地址:https://www.cnblogs.com/veryFuelong/p/13356985.html
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