Many beginners will use windows as a development machine, today we will see how to install Python virtual machine environment in win10 and Linux respectively. Virtual environments have a lot of advantages, today we use the virtual environment is virtualenv.
virtualenv is used to create independent Python environments, where multiple Pythons are independent of each other and do not affect each other, and it can:
1. Installation of new packages without permissions
2. Different applications can use different versions of the suite
3. Package upgrades do not affect other applications
Installation under win10
1. Open cmd to install the virtual environment package
pip install virtualenvwrapper-win
2. Configuring environment variables
WORKON_HOME
E:\Python_Envs
3. Open a new cmd window and install the virtual environment.
Create two pure virtual environments
mkvirtualenv --python=C:\SoftWare\Python27\ python27 deactivate mkvirtualenv --python=C:\SoftWare\Python36\ python36 deactivate
Establishment of a virtual environment for use
mkvirtualenv --python=C:\SoftWare\Python27\ py27 deactivate mkvirtualenv --python=C:\SoftWare\Python36\ py36 deactivate
Installation of common packages (Python36)
workon py36 pip install PIL pip install pymysql pip install django deactivate
Command Introduction
mkvitualenv Env create virtual environment --python can specify python version
workon Viewing Virtual Environments
workon Env Enter the virtual environment
pip list View the list of installed packages --format=columns
Specify the display mode
deactivate Exits the virtual environment
Installation under Linux
mounting
sudo apt-get install python-virtualenv
Usage
virtualenv [name of virtual environment]
E.g., create a **ENV** virtual environment
virtualenv ENV
By default, the virtual environment will depend on the site packages in the system environment, that is to say, third-party packages already installed in the system will also be installed in the virtual environment, if you do not want to depend on these packages, then you can add the parameter --no-site-packages to create a virtual environment
virtualenv --no-site-packages [Virtual Environment Name]
Starting a virtual environment
cd ENV source ./bin/activate
Note that at this point the command line will have one more (ENV), ENV is the name of the virtual environment, and all the next modules will only be installed into that directory.
Exiting the virtual environment
deactivate
Installing the Python Suite in a Virtual Environment
Virtualenv comes with a pip installer, so packages that need to be installed can be run directly:
pip install [Kit Name]
If the virtual environment is not started and the pip tool is installed on the system, the suite will be installed on the system environment, to avoid this matter, you can add it to the ~/.bashrc file:
export PIP_REQUIRE_VIRTUALENV=true
Or let the system automatically turn on the virtual environment when pip is executed:
export PIP_RESPECT_VIRTUALENV=true
Virtualenvwrapper
Virtaulenvwrapper is an extension package for virtualenv for easier management of virtual environments, and it can do:
1. Consolidate all virtual environments under one directory
2. Managing (adding, deleting, copying) virtual environments
3. Switching virtual environments
4. ...
mounting
sudo easy_install virtualenvwrapper
At this point you can not use virtualenvwrapper, the default virtualenvwrapper installed in /usr/local/bin below, in fact, you need to run the file to be able to, do not rush, open this file to see, there are installation steps, we follow the operation of the environment to set up a good.
Create a directory to store the virtual environment
mkdir $HOME/.virtualenvs
Add lines to ~/.bashrc:
export WORKON_HOME=$HOME/.virtualenvs
Add lines to ~/.bashrc:
source /usr/local/bin/
Running:
source ~/.bashrc
At this point virtualenvwrapper is ready to use.
This is the whole content of this article, I hope it will help you to learn more.