第六篇：python基础_6 内置函数与常用模块（一）

本篇内容

内置函数
匿名函数
re模块
time模块
random模块
os模块
sys模块
json与pickle模块
shelve模块

一、内置函数

1.定义

内置函数又被称为工厂函数。

2.常用的内置函数

（1）abs()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(abs(-1))

（2）all()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(all([1,2,'a',None]))

print(all([]))

（3）any()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(any([]))

print(any([' ',None,False]))

print(any(['',None,False]))

print(any(['',None,False,1]))

（4）bin(),oct(),hex()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(bin(10))

print(oct(10))

print(hex(10))

（5）bytes()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

#unicode----encode----->bytes

print('hello'.encode('utf-8'))

print(bytes('hello',encoding='utf-8'))

（6）callable()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(callable(bytes))

print(callable(abs))

（7）chr(),ord()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(chr(65))

print(chr(90))

print(ord('#'))

（8）int()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

x=1

print(type(x))

x=int(2)

print(type(x))

complex()、float()、str()、list()、tuple()、dict()与int()同理

（9）set()，可变集合

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

s={1,2,3,4}

print(type(s))

（10）frozenset()，不可变集合

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

s1=frozenset({1,2,3,4})

print(type(s1))

（11）dir()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import sys

#sys.path

# sys.argv

print(dir(sys))

（12）divmod()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(divmod(10,3))

print(divmod(102,20))

（13）enumerate()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

l=['a','b','c']

res=enumerate(l)

for i in res:

    print(i)

for index,item in enumerate(l):

    print(index,item)

（14）globals(),locals()，查看全局作用域和局部作用域

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(globals())

（15）hash()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(hash('abcdefg123'))

print(hash('abcdefg123'))

（16）help()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

def func():

    '''

    test function

    :return:

    '''

    pass

print(help(func))

（17）id()，是python解释器实现的功能，只是反映了变量在内存的地址，但并不是真实的内存地址

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

x=1

print(id(x))

def func():

    pass

print(id(func))

print(func)

（18）isinstance()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

x=1

print(type(x) is int)

print(isinstance(x,int))

（19）max(),min()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(max([1,2,3,10]))

print(max(['a','b']))

print(min([1,2,3,10]))

（20）pow()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(pow(3,2,2)) #3**2%2

（21）repr(),str()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(type(str(1)))

print(type(repr(1)))

（22）reversed()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

l=[1,'a',2,'c']

print(list(reversed(l)))

print(l)

（23）slice()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

l=[1,2,3,4,5,6]

print(l[0:4:2])

s=slice(0,4,2)

print(l[s])

（24）sorted()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

l=[1,10,4,3,-1]

print(sorted(l,reverse=True))

（25）sum()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(sum([1, 2,3]))

print(sum(i for i in range(10)))

（26）vars()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import m1

print(vars(m1) == m1.__dict__)

（27）zip()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

s='helloss'

l=[1,2,3,4,5]

print(list(zip(s,l)))

（28）__import__()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import sys

m_name=input('module>>: ')

if m_name == 'sys':

    m=__import__(m_name)

    print(m)

    print(m.path)

sys=__import__('sys')

print(sys)

（29）round()

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

print(round(3.565,2))

print(round(3.555,2))

二、匿名函数

1.定义

匿名函数：

（1）没有名字。

（2）函数体自带return。

匿名函数的应用场景：
应用于一次性的场景，临时使用。

2.使用

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

def func(x,y,z=1):

    return x+y+z

print(func)

print(func(1,2,3))

print(lambda x,y,z=1:x+y+z)

f=lambda x,y,z=1:x+y+z

print(f)

print(f(1,2,3))

三、 re模块

（1）

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

print(re.findall('\w','hello_ | yanglei 123'))

print(re.findall('\W','hello_ | yanglei 123'))

print(re.findall('\s','hello_ | yanglei 123 \n \t'))

print(re.findall('\S','hello_ | yanglei 123 \n \t'))

print(re.findall('\d','hello_ | yanglei 123 \n \t'))

print(re.findall('\D','hello_ | yanglei 123 \n \t'))

print(re.findall('h','hello_ | hello h yanglei 123 \n \t'))

print(re.findall('\Ahe','hello_ | hello h yanglei 123 \n \t'))

print(re.findall('^he','hello_ | hello h yanglei 123 \n \t'))

print(re.findall('123\Z','hello_ | hello h yanglei 123 \n \t123'))

print(re.findall('123$','hello_ | hello h yanglei 123 \n \t123'))

print(re.findall('\n','hello_ | hello h yanglei 123 \n \t123'))

print(re.findall('\t','hello_ | hello h yanglei 123 \n \t123'))

（2）. [] [^]

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

#.本身代表任意一个字符

print(re.findall('a.c','a a1c a*c a2c abc a c aaaaaac aacc'))

#[]内部可以有多个字符，但是本身只配多个字符中的一个

print(re.findall('a[0-9][0-9]c','a a12c a1c a*c a2c a c a\nc',re.S))

print(re.findall('a[a-zA-Z]c','aac abc aAc a12c a1c a*c a2c a c a\nc',re.S))

print(re.findall('a[^a-zA-Z]c','aac abc aAc a12c a1c a*c a2c a c a\nc',re.S))

print(re.findall('a[\+\/\*\-]c','a-c a+c a/c aac abc aAc a12c a1c a*c a2c a c a\nc',re.S))

（3）\：转义

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

print(re.findall(r'a\\c','a\c abc'))

（4）? * + {}：左边有几个字符，如果有的话，贪婪匹配

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

#?左边那一个字符有0个或者1个

print(re.findall('ab?','aab a ab aaaa'))

#*左边那一个字符有0个或者无穷个

print(re.findall('ab*','a ab abb abbb abbbb bbbbbb'))

print(re.findall('ab{0,}','a ab abb abbb abbbb bbbbbb'))

#+左边那一个字符有1个或者无穷个

print(re.findall('ab+','a ab abb abbb abbbb bbbbbb'))

print(re.findall('ab{1,}','a ab abb abbb abbbb bbbbbb'))

#{n,m}左边的字符有n-m次

print(re.findall('ab{3}','a ab abb abbb abbbb bbbbbb'))

print(re.findall('ab{2,3}','a ab abb abbb abbbb bbbbbb'))

（5）.* .*?

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

#.*贪婪匹配

print(re.findall('a.*c','a123c456c'))

#.*?非贪婪匹配

print(re.findall('a.*?c','a123c456c'))

（6）|

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

print(re.findall('company|companies','Too many companies have gone bankrupt, and the next one is my company'))

print(re.findall('compan|companies','Too many companies have gone bankrupt, and the next one is my company'))

（7）()：分组

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

print(re.findall('ab+','abababab123'))

print(re.findall('ab+123','abababab123'))

print(re.findall('ab','abababab123'))

print(re.findall('(ab)','abababab123'))

print(re.findall('(a)b','abababab123'))

print(re.findall('a(b)','abababab123'))

print(re.findall('(ab)+','abababab123'))

print(re.findall('(?:ab)+','abababab123'))

print(re.findall('(ab)+123','abababab123'))

print(re.findall('(?:ab)+123','abababab123'))

print(re.findall('(ab)+(123)','abababab123'))

print(re.findall('compan(y|ies)','Too many companies have gone bankrupt, and the next one is my company'))

print(re.findall('compan(?:y|ies)','Too many companies have gone bankrupt, and the next one is my company'))

（8）re的其他方法

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import re

print(re.findall('ab','abababab123'))

print(re.search('ab','abababab123').group())

print(re.search('ab','12aasssdddssssssss3'))

print(re.search('ab','12aasssdddsssssssab3sssssss').group())

print(re.search('ab','123ab456'))

print(re.match('ab','123ab456'))

print(re.split('b','abcde'))

print(re.split('[ab]','abcde'))

print(re.sub('xiaolan','xiaohong','xiaolan make love xiaolan xiaolan',1))

print(re.subn('xiaolan','xiaohong','xiaolan make love xiaolan xiaolan',1))

print(re.sub('(\w+)(\W+)(\w+)(\W+)(\w+)',r'\5\2\3\4\1','Toms make love'))

print(re.sub('(\w+)( .* )(\w+)',r'\3\2\1','Toms make love'))

obj=re.compile('\d{2}')

print(obj.search('abc123eeee').group())

print(obj.findall('abc123eeee'))

四、time模块

模块方法

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import time

print(time.time())

print(time.strftime('%Y-%m-%d %X'))

print(time.localtime())

print(time.gmtime()) #UTC

print(time.localtime().tm_mon)

print(time.localtime(123123123))

print(time.gmtime(123123123))

print(time.mktime(time.localtime()))

print(time.strftime('%Y',time.gmtime()))

'2017-03-01'

print(time.strptime('2017-03-01','%Y-%m-%d'))

print(time.ctime(12312312))

print(time.asctime(time.gmtime()))

五、random模块

1.模块方法

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import random

print(random.sample([1,'23',[4,5]],2))

print(random.uniform(1,3))

item=[1,3,5,7,9]

random.shuffle(item)

print(item)

2. 生成秘钥应用

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import random

def make_code(n):

    res=''

    for i in range(n):

        s1=str(random.randint(0,9))

        s2=chr(random.randint(65,90))

        res+=random.choice([s1,s2])

    return res

print(make_code(10))

六、os模块

模块方法

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import os

print(os.listdir('.'))

print(os.stat('m1.py').st_size)

print(os.sep)

print(os.linesep)

print(os.pathsep)

print([os.sep,os.linesep,os.pathsep])

res=os.system('dir .')

print('====?>',res)

print(os.path.dirname(r'C:\a\b\c\d\a.txt'))

print(os.path.basename(r'C:\a\b\c\d\a.txt'))

print(os.path.split(r'C:\a\b\c\d\a.txt'))

print(os.stat('m1.py').st_atime)

print(os.stat('m1.py').st_size)

print(os.path.getsize('m1.py'))

print(os.path.join('C:\\','a','b','c','d.txt'))

print(os.path.join('C:\\','a','b','D:\\','c','d.txt'))

print(os.path.normcase('c:/wiNdows\\system32\\')  )

print(os.path.normpath('c://wIndows\\System32\\../Temp/')  )

a='/Users/jieli/test1/\\\a1/\\\\aa.py/../..'

print(os.path.normpath(a))

print(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

BASE_DIR=os.path.normpath(os.path.join(

    os.path.abspath(__file__),

    '..',

    '..'

)

)

print(BASE_DIR)

七、sys模块

模拟进度条应用

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import sys,time

def progress(percent,width=50): #51

    if percent >= 100:

        # print('\r[%s] 100%%' %(width*'#'))

        percent=100

    show_str=('[%%-%ds]' %width) %(int(width*percent/100)*'#')

    print('\r%s %d%%' %(show_str,percent),file=sys.stdout,flush=True,end='')

#

total_size=1025121

recv_size=0

while recv_size < total_size:

    time.sleep(0.01) #模拟下载的网络延迟

    recv_size+=1024

    recv_per=int(100*recv_size/total_size)

    progress(recv_per,width=10)

八、json与pickle模块

（1）json

应用平台广泛

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import json

dic={'name':'yanglei','age':23}

print(type(json.dumps(dic)))

with open('a.json','w') as f:

    f.write(json.dumps(dic))

with open('a.json','r') as f:

    data=f.read()

    dic=json.loads(data)

    print(dic['name'])

dic={'name':'yanglei','age':23}

json.dump(dic,open('b.json','w'))

print(json.load(open('b.json','r'))['name'])

with open('c.json','r') as f:

    data=f.read()

    #[null,true,false,1]

    eval(data)

（2）pickle

只对python有效

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import pickle

dic={'name':'yanglei','age':23}

print(pickle.dumps(dic))

with open('d.pkl','wb') as f:

    f.write(pickle.dumps(dic))

with open('d.pkl','rb') as f:

    dic=pickle.loads(f.read())

    print(dic['name'])

dic={'name':'yanglei','age':23}

pickle.dump(dic,open('e.pkl','wb'))

print(pickle.load(open('e.pkl','rb'))['name'])

def func():

    print('from func')

import json

print(json.dumps(func))

import pickle

print(pickle.dumps(func))

pickle.dump(func,open('func.pkl','wb'))

九、shelve模块

模块方法

#!/usr/binl/env python

#encoding: utf-8

#author: YangLei

import shelve

f=shelve.open(r'sheve.shl')

f['yanglei']={'age':23,'pwd':'123456'}

f['xiaolan']={'age':18,'pwd':'123456'}

f.close()

obj=shelve.open(r'sheve.shl')

print(obj['yanglei'])

print(obj['xiaolan'])

obj.close()

for i in obj:

    print(i,obj[i])