most useful python modules

Serialization modules: JSON and PickleTwo modules for serialization JSON, used to convert between string and Python data types Pickle for conversion between Python-specific types and Python data types The JSON module provides four functions: dumps, dump, lo

parameter, indicating the error message is unsuccessful.The Sys.modules method maps the name of the module to a module that is actually present and applies only to modules that are currently imported.There are 3 module variables: Sys.stdin, sys.stdout, Sys.stderr They are class file (File-like) stream objects.Four, sys module case code demoAbove is the demo code for the Python sys module, and the gray part

This article mainly introduces the simple Getting Started Guide for the defaultdict module and namedtuple module in Python. efaultdict inherits from dict, namedtuple inherits from tuple, and is the built-in data type in Python, for more information, see the built-in data types in Python, such as int, str, list, tuple, and dict. The collections module of

Development package Python-devel)14. Fabric is a python-based SSH command-line tool that simplifies the application deployment and system management tasks of SSH, which provides a system-based operational component that enables local or remote shell commands, including command execution, file upload, download, and full execution log output. The fabric is packaged in a higher level of paramiko, making it ea

The OS module provides new/delete/view file properties for directories or files, as well as path operations for files and directories. For example: absolute path, parent directory ... However, the operation of the OS file should also include operations such as mobile replication packaging compression decompression, which are not available in these OS modules. The shutil in this article is the addition of file operations in the OS. --Mobile Copy packag

This article mainly introduces how the MySQLdb and torndb modules in Python handle MySQL disconnection issues. torndb is more concise to use, for more information about how to use python to refine the wordpress tag code, see the error when calling the MySQLdb module, after checking the code for a long time, no problem was found in the code. Later, I asked the mas

In Python, The MySQLdb and torndb modules handle MySQL disconnection issues, and mysqldbtorndb When using python to refine the wordpress tag code, you may encounter an error when calling the MySQLdb module. The error prompt is very different from the cause, after checking the code for a long time, no problem was found in the Code. Later, I asked the master, and I

Today, do a test that would like to refer to the upper directory in the current Python module; Uh, a search.Let's look at the directory situation:[Email protected] test]# tree.├──t1.py├──t2│└──t2.py└──xxu└──test.py2 directories, 3 filesIn fact, the first thing you want to do is to call the t1.py function in test.py:Direct use of the effect:[email protected] xxu]# cat test.py #/usr/bin/env python#coding:utf-

instance:>>> obj = [u ' foo ', {u ' bar ': [u ' Baz ', None, 1.0, 2]}]>>> Str_json = ' [' foo ', {' bar ': [' Baz ', NULL, 1.0, 2]}] ' >>> obj2 = json.loads (Str_json) >>> print obj2[u ' foo ', {u ' bar ': [u ' Baz ', None, 1.0, 2]}]>>> Obj2 = = ObjtrueBig Data processing:The dumps and deserialization of the loads, regardless of the time of serialization. The data being targeted is either a JSON string or a Python data structure. So when a lot of JSO

('%b ') #print:%b:september print '%%b:%s '% DT.STRFT IME ('%B ') #print: datetime%c:09/12/12 23:04:27 print ' datetime%%c:%s '% dt.strftime ('%c ') #print: Date%X:09/12/12 print ' date percent x:%s '% dt.strftime ('%x ') #print: Time%x:23:04:27 print ' time%%x:%s '% dt.strftime ('%x ') #print: Today is the 3rd day of this week print ' Today is this week's %s days '% dt.strftime ('%w ') #print: Today is the NO. 256 day of this year print ' Today is this year's%s day '% dt.strftime ('%j ') #prin

This article describes the operating system of common python modules in detail, which has some reference value. if you are interested, refer to the operating system module for interaction between python and the operating system. Common functions are as follows: OS. getcwd () gets the current working path of the python

Module is the code that encapsulates a particular function.The modules are divided into three types:1. Custom Modules2; third-party modules3. Built-in ModulesOne, custom moduletest.py#!/usr/bin/env python#-*-Coding:utf-8-*-Print ("I am Test")Print ("I am Test1")Print ("Hello World")sys.py (the file calls the test module)#!/usr/bin/env python#-*-Coding:utf-8-*-Imp

A. Module1. Definition: Contains the Python definition and the declaration file, the file name is the module name plus the. py suffix.Import loaded modules are divided into four categories:Code written in 1.Python (. py file)2. C or C + + extensions that have been compiled as shared libraries or DLLs3. Package a set of modules4. Built-in

Module overviewIf the module is a logical way to organize Python code, then the file is the method of organizing the module on the physical layer.Therefore, * * A file is considered a standalone module, and a module can also be viewed as a file. The file name of the module is moduloThe name of the block plus the extension. py. Unlike other languages in which you can import classes (Class), you are importing module or module properties in

Reference One, PackageA package is a folder that is used to store modules and sub-packages.There is usually a __init__.py file (or no) in the package.There will be a __pycache__ folder in the package that holds the intermediate bytecode (binary files) that the. py file is interpreted by the interpreter.Second, the moduleFiles that can be used as modules have . py,. PYc,. Pyo,. PYD,. So,.dll files.Iii.. pyc

1, Module IntroductionMany functions are grouped by category and placed in separate files. In Python, a. py file is called a module. In other languages, it is called a class library.What are the benefits of using modules?(1) Greatly improve the maintainability of the Code;(2) Writing code does not have to start from scratch.Categories of modules:Built-in modules,

numbers (note: is one). To invert the character set, you can place ' ^ ' at the beginning of the string, such as ' [^ABC] ' to match any character except A,b,c. Note: If you want to '. ', ' * ', '? ' These special characters are used as literal characters and are escaped with ' \ ', but are not necessary in the character set, although they are legal (because you can adjust the order to resolve them). Remember the following two rules: A. If ' ^ ' appears at the beginning of the character set, it

command to install Python Imaging Library is: pip install PIL Wait patiently for the download and installation before you can use PIL. With PIL, image processing is easy. Generate a thumbnail for any image: >>> import Image>>> im = Image.open('test.png')>>> print im.format, im.size, im.modePNG (400, 300) RGB>>> im.thumbnail((200, 100))>>> im.save('thumb.jpg', 'JPEG') Other commonly used third-party libraries include MySQL driver: MySQL-

Reference custom modules in Python After learning Python for a short period of time, it has never been stuck in simple syntax and cannot really understand the power of Python. I learned how to reference a custom module today. When a module is referenced, the compiler will first find the referenced module in the curren

In Python, the installation of a third-party module is done through the Package management tool PIP.Generally speaking Third-party libraries will be registered in the official Python pypi.python.org website, to install a third-party library, you must first know the name of the library, you can search on the official website or pypi, such as pillow name is called pillow, so the installation of Pillow command