Virtual Environment

The use of a Virtual Environment is to test python code in encapsulated environments, and to also avoid filling the base Python installation with libraries we might use for only one project.

virtualenv

Install virtualenv
```
pip install virtualenv
```
Install virtualenvwrapper-win (Windows)
```
pip install virtualenvwrapper-win
```

Usage:

Make a Virtual Environment named HelloWorld
```
mkvirtualenv HelloWorld
```
Anything we install now will be specific to this project. And available to the projects we connect to this environment.
Set Project Directory
To bind our virtualenv with our current working directory we simply enter:
```
setprojectdir .
```
Deactivate
To move onto something else in the command line type deactivate to deactivate your environment.
```
deactivate
```
Notice how the parenthesis disappear.
Workon
Open up the command prompt and type workon HelloWorld to activate the environment and move into your root project folder
```
workon HelloWorld
```

Poetry

From Poetry website

Poetry is a tool for dependency management and packaging in Python. It allows you to declare the libraries your project depends on and it will manage (install/update) them for you.

Install Poetry
```
pip install --user poetry
```

Create a new project

poetry new my-project

This will create a my-project directory:

my-project
├── pyproject.toml
├── README.rst
├── poetry_demo
│   └── __init__.py
└── tests
    ├── __init__.py
    └── test_poetry_demo.py

The pyproject.toml file will orchestrate your project and its dependencies:

[tool.poetry]
name = "my-project"
version = "0.1.0"
description = ""
authors = ["your name <your@mail.com>"]

[tool.poetry.dependencies]
python = "*"

[tool.poetry.dev-dependencies]
pytest = "^3.4"

Packages
To add dependencies to your project, you can specify them in the tool.poetry.dependencies section:
```
[tool.poetry.dependencies]
pendulum = "^1.4"
```
Also, instead of modifying the pyproject.toml file by hand, you can use the add command and it will automatically find a suitable version constraint.
```
$ poetry add pendulum
```
To install the dependencies listed in the pyproject.toml:
```
poetry install
```
To remove dependencies:
```
poetry remove pendulum
```

For more information, check the documentation or read here:

Pipenv

From Pipenv website

Pipenv is a tool that aims to bring the best of all packaging worlds (bundler, composer, npm, cargo, yarn, etc.) to the Python world. Windows is a first-class citizen, in our world.

Install pipenv
```
pip install pipenv
```
Enter your Project directory and install the Packages for your project
```
cd my_project
pipenv install <package>
```
Pipenv will install your package and create a Pipfile for you in your project’s directory. The Pipfile is used to track which dependencies your project needs in case you need to re-install them.
Uninstall Packages
```
pipenv uninstall <package>
```
Activate the Virtual Environment associated with your Python project
```
pipenv shell
```
Exit the Virtual Environment
```
exit
```

Find more information and a video in docs.pipenv.org.

Anaconda

Anaconda is another popular tool to manage python packages.

Where packages, notebooks, projects and environments are shared. Your place for free public conda package hosting.

Usage:

Make a Virtual Environment
```
conda create -n HelloWorld
```
To use the Virtual Environment, activate it by:
```
conda activate HelloWorld
```
Anything installed now will be specific to the project HelloWorld
Exit the Virtual Environment
```
conda deactivate
```