A Virtual Environment, allows to create an isolated working copy of Python. It is quite common situation when Python applications use packages that are not part of the standard library. It happens that multiple applications may require different version of the same library. In other words- single installation of Python will not be able to serve all the possible requirements for applications. This issue can be solved by utilizing Virtual environments. Virtual environment is directory that contains all the Python installation and all the required packages. Different Python application may use dedicated virtual environments.
Starting Python 3.6 - virtual environment creation module shipped as part of Python installation.
Here is example - how to create virtual environment using Python 3.6
This command creates new forlder "env" in current directory (if directory not yet exists). It also create subdirectories in "env" directory that containing a copy of the Python interpreter, the standard library, supporting files, etc.
After virtual environment is created- it needs to be activated:
Depend on OS type- it can be done in several ways.
For Windows:
.\env\Scripts\activate.bat
For Linux:
./env/Scripts/activate.sh
After virtual environment is activated- shell will show activated virtual environment as a prefix in command prompt: (venv).
Now we can install all the required libraries for our current Python application.
For example:
python -m pip install beautifulsoup4
python -m pip install lxml
All the installed packages will be stored inside of "venv" folder and not overlap/affect any other Python applications.
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