# Python Virtual Environment

## Overview
| Action | Command |
| - | - |
| <a href="#install-required-packages">Install</a> | `sudo apt install python3-venv` |
| <a href="#create">Create</a> | `python3 -m venv .venv` |
| <a href="#activate">Activate</a> | `source .venv/bin/activate` |
| <a href="#deactivate">Deactivate</a> | `deativate` |

## Install Required Packages
```bash
sudo apt install python3-venv
```
- installiert das python modul venv zum erstellen von virtual environments

## Create
```bash
python3 -m venv .venv
```
- executes python3 of PATH (? default python3 of the system)
- executes modul venv (for virtual environment)
- creates new directory .venv
- initializes virtual python environment in .venv/
- creates the following structure:
```
    /home/<user>/<project>/
    |---.venv/
    |    |--- bin/
    |    |--- lib/
    |    |--- ...
    |--- <myprogram.py>
```

## Activate
```bash
source .venv/bin/activate
```
- activates the python virtual environment within .venv/
    - all following python executions are made from within this virtual environment
- console inserts virtual environment name at beginning:
```bash
(venv) <user>@raspberrypi:~/<project> $
```
### Alternative
- alternatively the python virtual environment can directly be called (e.g. from scripts):
```bash
/home/<user>/<project>/.venv/bin/python ...
```


## Deactivate
```bash
deactivate
```
- deactivates the active virtual environment