Python third-party library installation Tips

This article source address Http://www.jianshu.com/p/9acc85d0ff16

Pythonis an elegant language, concise grammar, powerful features. Of course, the rich third-party library, more able to accelerate the development. So the question is, how do you install these third-party libraries (packages)?

There are few ways to install third-party libraries. Here are some tips.

Source Installation

Many third-party libraries are open source, almost all can github find the source code on or PyPI. Find the source format is probably zip all tar.zip , tar.bz2 the format of the compressed package. Unpack the packages and go to the Unpacked folder, and you'll usually see a setup.py file. Open the command line and go to the folder. Run (on the command line)

Python setup.py Install

This command, you can install the third library into the system, that is, your Python path, windows presumably in C:\Python\Lib\site-packages .
Linuxwill be in /usr/local/lib/python2.7/dist-packages .
Macshould be in /Library/Python/2.7/site-packages . If installed in an virtulenv environment, the package is installed in a directory under the established virtual Environment site-packages/ . To uninstall these libraries is also very simple, enter site-packages , directly delete the library file is OK. Of course, these installations may be a little cumbersome, need to download, unzip, and then run the installation, uninstall is not very convenient. Is there a tool that can help manage these libraries outside?

Package Manager (PIP and Easy_install)

Many programming languages now come with package managers, for example Ruby gem nodejs npm . Pythonof course, there is no exception, pip with easy_install the famous and.

As mentioned above pypi is the python source of some third library, use pip or easy_install install the module, will search this source, and then automatically download the installation. For example we need to install the flask framework specific commands as follows:

Pip Install flask

Or

Easy_install Flask

Simple, a simple command is done. Uninstall is also very convenient, for example we need to uninstallflask

Pip Uninstall flask

View the installed packages, including the system's own and manually installed

PIP List

You can also search for packages

Pip Search Flask

You can also redirect the libraries that the output project uses.

Pip Freeze > Requirements.txt

This will redirect the third-party library in the environment to the requirements.txt file, and if you give others a dependency on the project, you only need to run:

Pip Install-r requirements.txt

It's very convenient. Of course, sometimes, our network is not so smooth, pip is installed online, can you leave floss? Of course, pip install the first step is to pypi look for the package, and then download it locally. If the network is not good, you can first build a local warehouse, the commonly used packages offline download. such as flask the source code can be downloaded

Pip Intall flask-master.zip

It can also be installed.

The latest version of PIP also supports Git installation and only needs to use its git address.

Pip Install Git+https://github.com/kennethreitz/requests.git

But this installation is quite slow. It is the original clone to a local temporary directory, and then install the ZIP package.

virtual Environment Related installation

Of course, the above mentioned, in fact, is also very common, but also not what skills. Here are some tips for understanding the principles and solving unconventional problems.

Using Python , we would like to build a virtual environment virtualenv , for example, to create a venv virtual environment. We just need to source go in and we can use pip the installation. However, sometimes, even in a virtual environment, using sudo the prefix ( windows ignore), then the installed library is not in the virtual environment, but is installed in the directory under the system site-package .

windowsUsers may be happy and do not need to be aware of this issue. Of course, windows it also has its own problems. On the windows installation python , it is generally a compiled binary package exe executable file. Usually there are 32-bit and 64-bit python . For third-party libraries, there would not be much difference between 32 and 64. However, for some C written python libraries, such as,, mysqldb PIL pillow will find the use pip or easy_install the way will be error:

Fixing Python error:unable to find Vcvarsall.bat

The reason is probably windows missing some C compiler stuff. The source code needs to compile to install, at this time windows very bitter force. Of course, there are some good-hearted people, help you to compile some of the commonly used libraries into EXE executable files, put to this site. You just need to look for the version, download one-click Install.

However, there is a problem, download exe files, run the installation, this library is installed in the directory of the system site-package , if I am windows building a venv virtual environment, so that the installation is not a break food?

Don't worry, the real trick in this article is to solve the problem. Let's install the 64-bit mysqldb . Download MySQL?python?1.2.5.win?amd64?py2.7.exe It first windows , and use the command line to enter the virtual environment venv . And then run

easy_install MySQL?python?1.2.5.win?amd64?py2.7.exe

Perfect solution, in a venv virtual environment, the mysqldb library is installed to the venv next.

With the top three ways, the third- python Party library installation covers almost all platforms. However, even though it Python is a cross-platform, development environment, it is best to use Linux or MacOS , the two systems have better tools and save a lot of puzzling problems.

Python third-party library installation Tips