• 内置函数


     abs

     取绝对值

     all

    print(all([1,-3,3]))#有不为0的就是真
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 True
    3 
    4 Process finished with exit code 0
    执行结果

     any

    print(any([1,-3,0])) #有一个为真就为真
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 True
    3 
    4 Process finished with exit code 0
    执行结果

     ASCII

    print(ascii([1,-3,'大大勾拳'])) #把内存的数据对象变成一个可打印的字符串
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 [1, -3, 'u5927u5927u52feu62f3']
    3 
    4 Process finished with exit code 0
    执行结果

     bin

    print(bin(255)) #把数字从十进制转二进制
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 0b11111111
    3 
    4 Process finished with exit code 0
    执行结果

     bool

    print(bool([]))#判断真假,有数据就是真,没有数据就是假
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 False
    3 
    4 Process finished with exit code 0
    执行结果

     bytearry

    b=bytearray('abcde',encoding='utf-8')#字节数组  可修改的二进制
    print(b[1])
    b[1]=50             #把二进制变成数组的格式,并且可以进行修改
    print(b)
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 98
    3 bytearray(b'a2cde')
    4 
    5 Process finished with exit code 0
    执行结果

     callable

    def as1():pass
    print(callable([])) #判断是否可以被调用
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 False
    3 
    4 Process finished with exit code 0
    执行结果

      chr

    print(chr(97))  #数字对应的asc码,参数必须是数字
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 a
    3 
    4 Process finished with exit code 0
    执行结果

     ord

    print(ord('d'))#asc码对应的数字,参数必须是字符
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 100
    3 
    4 Process finished with exit code 0
    执行结果

     complie

    code ='for i in range(10):print(i)'         #把一段字符串变成可以编译的代码
    c=compile(code,'','exec')                   
    exec(c)                                     #直接exec()就可以,跟eval一样用,更简单
     1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
     2 0
     3 1
     4 2
     5 3
     6 4
     7 5
     8 6
     9 7
    10 8
    11 9
    12 
    13 Process finished with exit code 0
    执行结果

     exec

    把一段字符串变成可以编译的代码

    code ='for i in range(10):print(i)'         #把一段字符串变成可以编译的代码
    exec(code)       
     1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
     2 0
     3 1
     4 2
     5 3
     6 4
     7 5
     8 6
     9 7
    10 8
    11 9
    12 
    13 Process finished with exit code 0
    执行结果

     eval

    code ='1+2*3'         #把一段字符串变成可以编译的代码,针对整数加减乘除
     print(eval(code))
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 7
    3 
    4 Process finished with exit code 0
    执行结果

     divmod

    print(divmod(5,1))   #返回商跟余数
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 (5, 0)
    3 
    4 Process finished with exit code 0
    执行结果

     lambda

     匿名函数

    def sayhi(n):
        print(n)
    
    sayhi(5)
    
    cal=lambda  n :print(n)             #lambda 就是匿名函数,只能处理简单的
    cal(5)
    
    #或者简单的三元运算
    cal= lambda n:3 if n<4 else n
    print(cal(2))
    #需要配合filter使用,filter是过滤出自己想要的
    #也可配合map使用
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 5
    3 5
    4 3
    5 
    6 Process finished with exit code 0
    执行结果

     filter

     过滤自己想要的数据,配合lambda使用

    res=filter(lambda n:n>5,range(10))
    for i in res:
        print(i)
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 6
    3 7
    4 8
    5 9
    6 
    7 Process finished with exit code 0
    执行结果

     map

    把传入的每个值进行处理,再返回一个列表

    res=map(lambda  n:n*n,range(10))        ###filter是吧过滤出来的合格的打印出来,map是把传入的每一个值进行处理,再返回一个列表
    for i in res:                                                       
        print(i)
     1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
     2 0
     3 1
     4 4
     5 9
     6 16
     7 25
     8 36
     9 49
    10 64
    11 81
    12 
    13 Process finished with exit code 0
    执行结果

     reduce

    import  functools
    res=functools.reduce(lambda x,y:x+y,range(10))  #累加,把传入的值,进行处理,然后将结果累加起来
    print(res)
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 45
    3 
    4 Process finished with exit code 0
    执行结果

     frozenset

    冻结不可变的集合

    a= frozenset([1,4,33,212,33,35])  #set是有添加,清楚功能的,forozenset 没有这些功能了

    globals

    print(globals())        #返回的是当前整个程序里所以的key,valve格式,变量名是key,对应的变量是valve
    1 C:UsersAdministratorPycharmProjectsuntitled3venvScriptspython.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
    2 {'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x0045C490>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py', '__cached__': None}
    3 
    4 Process finished with exit code 0
    执行结果

     hash

     中文叫散列 通关一系列算法,把无序的数据转换成有映射关系的有序数据,就是哈希

     hex

     把一个数字转成16进制

     id

     返回内存地址

     iter

     迭代器

     max

     返回最大值

     next

     跟迭代器的__next__方法一样

     oct

     转八进制

    print(oct(8))#oct 转八进制
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 0o10
    3 
    4 Process finished with exit code 0
    执行结果

     pow

    print(pow(2,8)) #多少次方
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 256
    3 
    4 Process finished with exit code 0
    执行方法

     range

     循环

     repr

     用字符串表示对象

     reversed

     反转,类似列表的用法

     round

    print(round(1.3342,3))  #保留小数点后几位,参数可以调
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 1.334
    3 
    4 Process finished with exit code 0
    执行结果

     slice

    d=range(10) 
    d=list(d)
    print(d[slice(2,5)]) #切片
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 [2, 3, 4]
    3 
    4 Process finished with exit code 0
    执行结果

     sorted

     把字典排序

    a={1:3,2:11,99:3,-2:13}
    print(sorted(a))  #默认key
    print(sorted(a.items())) 
    print(sorted(a.items(),key=lambda x:x[1])) #a按照valve排序,valve不能有字符串
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 [-2, 1, 2, 99]
    3 [(-2, 13), (1, 3), (2, 11), (99, 3)]
    4 [(1, 3), (99, 3), (2, 11), (-2, 13)]
    5 
    6 Process finished with exit code 0
    执行结果

     sum

     求和

     vars

     返回一个对象的所有属性名,没啥用

     zip

     拉链的意思,组合两个列表,以元组的形式显示。

    a=[1,2,3,4,5]                   #如果a,b数量不一样,按照最少的来
    b=['a','b','c','d','e']
    
    for i in zip(a,b):
        print(i)
    print(type(i))
    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 (1, 'a')
    3 (2, 'b')
    4 (3, 'c')
    5 (4, 'd')
    6 (5, 'e')
    7 <class 'tuple'>
    执行结果

     __import__

     调用一个程序文件,有用,例如

    1 C:UsersqiangqlAppDataLocalProgramsPythonPython36-32python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
    2 welcome to index page
    3 username:qiangql
    4 password1234
    5 user has passed authentication
    6 welcome to home page
    7 waibu
    执行结果

    直接调用了111的内容。

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  • 原文地址:https://www.cnblogs.com/PYlog/p/8686008.html
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