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Python常用模块学习

1.模块介绍

2.time & datetime模块

3.random

4.os

5.sys

6.shutil

7.json&pickle

8.shelve

9.xml处理

10.yaml处理

11.configparser

12.hashlib

13.subprocess

14.logging模块

15.re正则表达式

1.模块

模块,就是用一坨代码实现了某个功能的代码集合。

类似于函数式编程和面向过程编程,函数式编程则完成一个功能,其他代码用来调用即可,提供了代码的重用性和代码间的耦合。而对于一个复杂的功能来说,则需要多个函数才能呢完成(函数又可以再不同的.py文件中),n个.py文件组成的代码集合就称为模块。

如:os是系统相关的模块;file是文件操作相关的模块

模块分为3种:

  • 自定义模块
  • 内置模块
  • 开源模块

自定义模块:

1.定义模块

情景一:

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情景二:

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情景三:

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2.导入模块

导入模块有以下几种方法:

 

1 import module
2 from module.xx.xx import xx
3 from module.xx.xx import xx as rename
4 from module.xx.xx import *

 

 导入模块其实就是告诉Python解释器去解释那个.py文件

 

 导入一个py文件,解释器解释该py文件

导入一个包,解释器解释该包下的_init_.py文件

那么问题来了,导入模块时是根据哪个路径作为基准来进行的呢?即:sys.path

技术分享
import sys
print sys.path
结果:
[/Users/wupeiqi/PycharmProjects/calculator/p1/pp1, /usr/local/lib/python2.7/site-packages/setuptools-15.2-py2.7.egg, /usr/local/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg, /usr/local/lib/python2.7/site-packages/MySQL_python-1.2.4b4-py2.7-macosx-10.10-x86_64.egg, /usr/local/lib/python2.7/site-packages/xlutils-1.7.1-py2.7.egg, /usr/local/lib/python2.7/site-packages/xlwt-1.0.0-py2.7.egg, /usr/local/lib/python2.7/site-packages/xlrd-0.9.3-py2.7.egg, /usr/local/lib/python2.7/site-packages/tornado-4.1-py2.7-macosx-10.10-x86_64.egg, /usr/local/lib/python2.7/site-packages/backports.ssl_match_hostname-3.4.0.2-py2.7.egg, /usr/local/lib/python2.7/site-packages/certifi-2015.4.28-py2.7.egg, /usr/local/lib/python2.7/site-packages/pyOpenSSL-0.15.1-py2.7.egg, /usr/local/lib/python2.7/site-packages/six-1.9.0-py2.7.egg, /usr/local/lib/python2.7/site-packages/cryptography-0.9.1-py2.7-macosx-10.10-x86_64.egg, /usr/local/lib/python2.7/site-packages/cffi-1.1.1-py2.7-macosx-10.10-x86_64.egg, /usr/local/lib/python2.7/site-packages/ipaddress-1.0.7-py2.7.egg, /usr/local/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg, /usr/local/lib/python2.7/site-packages/pyasn1-0.1.7-py2.7.egg, /usr/local/lib/python2.7/site-packages/idna-2.0-py2.7.egg, /usr/local/lib/python2.7/site-packages/pycparser-2.13-py2.7.egg, /usr/local/lib/python2.7/site-packages/Django-1.7.8-py2.7.egg, /usr/local/lib/python2.7/site-packages/paramiko-1.10.1-py2.7.egg, /usr/local/lib/python2.7/site-packages/gevent-1.0.2-py2.7-macosx-10.10-x86_64.egg, /usr/local/lib/python2.7/site-packages/greenlet-0.4.7-py2.7-macosx-10.10-x86_64.egg, /Users/wupeiqi/PycharmProjects/calculator, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python27.zip, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old, /usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload, /usr/local/lib/python2.7/site-packages, /Library/Python/2.7/site-packages]
View Code

 如果sys.path路径列表没有你想要的路径,可以通过sys.path.append(‘路径’)添加

通过os模块可以获取各种目录

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1 import sys
2 import os
3 
4 pre_path = os.path.abspath(../)
5 sys.path.append(pre_path)
View Code

2.开源模块

一、下载安装

下载安装有两种方式:

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yum
pip
apt-get
方式一
技术分享方式二

 备注:

Python常用模块学习