Python Common Module Learning

1. Module Introduction

2.time & DateTime Module

3.random

4.os

5.sys

6.shutil

7.json&pickle

8.shelve

9.xml processing

10.yaml processing

11.configparser

12.hashlib

13.subprocess

14.logging Module

15.re Regular Expressions

1. Module

A module is a collection of code that implements a function with a single piece of code.

Like functional programming and process-oriented programming, functional programming accomplishes a function, and other code is used to invoke it, providing reusability of code and coupling between the code. For a complex function, multiple functions are required to complete (the function can be in a different. py file), and the Code collection consisting of N. py files is called a module.

such as: OS is a system-related module; file is a module related to the operation of files

The modules are divided into 3 types:

• Custom Modules
• Built-in Modules
• Open source Module

Custom modules:

1. Defining the Module

Scenario One:

Scenario Two:

Scenario Three:

？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？

2. Import the module

There are several ways to import the module:

1 Import Module 2  from Import xx 3  from Import xx as rename 4  from Import *

The import module actually tells the Python interpreter to explain the. py file

Import a py file, the interpreter interprets the py file

Import a package, the interpreter interprets the _init_.py file under the package

So the question is, which path will be used as the benchmark when importing the module? namely: Sys.path

ImportSYSPrintsys.path results: ['/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

If the Sys.path path list does not have the path you want, you can add it by sys.path.append (' path ')

Access to various catalogs via OS module

1 Import SYS 2 Import OS 3 4 Pre_path = Os.path.abspath ('.. /')5 sys.path.append (Pre_path)

View Code

2. Open source module

First, download the installation

There are two ways to download the installation:

yumpipapt-get

Way OneMode two

Note:

Python Common Module Learning