[PYTHON] virtualenv Basic command usage memo

Outline and purpose of this article

It is a basic command memo of virtualenv, a virtual environment creation tool in python.

Target person

• For memorandum of people who use virtualenv only occasionally and forget commands.
• (For those who have python development experience and have touched virtualenv.)

What is virtualenv?

• A virtual environment creation tool used in python development.
• A tool that allows you to create a clean virtual environment for each project.
• By introducing virtualenv, you can enjoy the following benefits.
• Since a development environment is created for each project, it is not necessary to pollute other projects or the global python environment on the machine during development.
• Easy to recreate even if the development environment during the project is broken.

Install virtualenv

Like any other python package, you can install it with the pip command.

$ pip install virtualenv

Creating a virtual environment

Cd to the project you want to create a virtual environment and hit the following command to create the virtual environment. The virtual environment name can be any name. From now on, we will use a virtual environment named my_env.

#Virtual environment my for a specific project_Create env.
$ cd (The project you want to create a virtual environment)
$ virtualenv my_env

Enable virtual environment

The virtual environment is not valid just by creating it You need to enable it as follows:

#Enable the virtual environment myenv
$ source myenv/bin/activate

#If the following is displayed on the console, it is successful.!
(myenv) $ 

#The virtual environment is clean when it is just created.
#If you try pip freeze, you will see that only the minimum number of packages are installed.
(myenv) $ pip freeze
appdirs==1.4.3
packaging==16.8
pyparsing==2.2.0
six==1.10.0

Disable / delete virtual environment

Do the following for each.

#Disable virtual environment
(myenv) $ deactivate

#Delete virtual environment
# (You can delete the entire folder created directly under the project.)
$ rm -rf myenv/