内置函数

 abs

 取绝对值

 all

print(all([1,-3,3]))#有不为0的就是真

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
True

Process finished with exit code 0

 any

print(any([1,-3,0])) #有一个为真就为真

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
True

Process finished with exit code 0

 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

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
[1, -3, '\u5927\u5927\u52fe\u62f3']

Process finished with exit code 0

 bin

print(bin(255)) #把数字从十进制转二进制

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
0b11111111

Process finished with exit code 0

 bool

print(bool([]))#判断真假，有数据就是真，没有数据就是假

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
False

Process finished with exit code 0

 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)

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
98
bytearray(b'a2cde')

Process finished with exit code 0

 callable

def as1():pass
print(callable([])) #判断是否可以被调用

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
False

Process finished with exit code 0

  chr

print(chr(97))  #数字对应的asc码，参数必须是数字

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
a

Process finished with exit code 0

 ord

print(ord('d'))#asc码对应的数字，参数必须是字符

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
100

Process finished with exit code 0

 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

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
0
1
2
3
4
5
6
7
8
9

Process finished with exit code 0

 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)       

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
0
1
2
3
4
5
6
7
8
9

Process finished with exit code 0

 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))

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
7

Process finished with exit code 0

 divmod

print(divmod(5,1))   #返回商跟余数

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
(5, 0)

Process finished with exit code 0

 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

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
5
5
3

Process finished with exit code 0

 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)

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
6
7
8
9

Process finished with exit code 0

 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)

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
0
1
4
9
16
25
36
49
64
81

Process finished with exit code 0

 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)

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
45

Process finished with exit code 0

 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

C:\Users\Administrator\PycharmProjects\untitled3\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/2018-2-27/测试.py
{'__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}

Process finished with exit code 0

 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

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
0o10

Process finished with exit code 0

 pow

print(pow(2,8)) #多少次方

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
256

Process finished with exit code 0

 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

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
1.334

Process finished with exit code 0

 slice

d=range(10) 
d=list(d)
print(d[slice(2,5)]) #切片

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
[2, 3, 4]

Process finished with exit code 0

 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

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
[-2, 1, 2, 99]
[(-2, 13), (1, 3), (2, 11), (99, 3)]
[(1, 3), (99, 3), (2, 11), (-2, 13)]

Process finished with exit code 0

 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))

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
(1, 'a')
(2, 'b')
(3, 'c')
(4, 'd')
(5, 'e')
<class 'tuple'>

 __import__

 调用一个程序文件，有用，例如

C:\Users\qiangql\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/qiangql/PycharmProjects/untitled/内置函数测.py
welcome to index page
username:qiangql
password1234
user has passed authentication
welcome to home page
waibu

直接调用了111的内容。

 

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