Python Fifth day Module (2)

module, which implements a set of code for a function with a mound code.

There are two ways to exist

1. Write to a folder

2.py file

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 may be required to complete (functions can be in different. py files), 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 three types:

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

Custom Modules

1. Define the module

2. Import Module

Python is used more and more widely, and to a certain extent relies on it providing programmers with a large number of modules to use, and if you want to use modules, you need to import them. There are several ways to import a 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, is the module being imported based on that path as a benchmark? namely: Sys.path

ImportSYSPrintSys.path Result: The default path is a list. ['/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']

If the Sys.path path list does not have the path you want, it can be added by Sys.path.append (' path '). (for which file to execute, Python will automatically add the folder that contains the file to the path of the module)
Various directories can be obtained through the OS module, for example:

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

__init__ is a special file, he will explain a folder by default, (a module must have a __init__ file, so that it is called a package, can be imported)Open source Module

Python Fifth day Module (2)