Python

Python is an interpreted high-level general-purpose programming language.

Index

• General
• Pip
• Virtualenv
• Conda
• PyInstaller

General

Print the version.

python --version

Print path.

python -c "import sys; print('\n'.join(sys.path))"

Run an HTTP server.

python -m http.server 8080

Pip

Pip is the package installer for Python.

Install.

apt install python3-pip

Update.

python -m pip install --upgrade pip

Install packages.

pip install <package>
pip install -r <requirements.txt>

Update package.

pip install --upgrade <package>

Export packages and versions.

pip freeze > <requirements.txt>

Uninstall package.

pip uninstall <package>

Virtualenv

Virtualenv is a tool to create isolated Python environments.

Install.

pip install virtualenv

Create a virtual environment.

python -m venv <env>

Activate a virtual environment.

source <env>/bin/activate
<env>\Scripts\activate.bat

Check Python location.

which python
where python

Deactivate a virtual environment.

deactivate
deactivate.bat

Conda

Conda is an open source package management system and environment management system.

General

Show version.

conda info

Update.

conda update conda

List available Python versions.

conda search python

Environments

Environments are located at:

• C:/ProgramData/Anaconda3/envs
• C:/Users/<user>/.conda/envs

List all the environments.

conda info --envs

Create a new environment.

conda create --name <env> python=<version>

Create an environment from a yml file.

conda env create --file <environment.yml>

Export an environment to a yml file.

conda env export > <environment.yml>

Clone an environment.

conda create --name <new> --clone <old>

Activate an environment.

source activate <env>
conda activate <env>

Deactivate an environment.

source deactivate
conda deactivate

Remove an environment.

conda remove --name <env> --all

Packages

List the packages.

conda list

Check if a package is installed in an environment.

conda list --name <env> <package>

Install a new package.

conda install <package>

Install packages from file.

conda install --file requirements.txt

Update a package.

conda update <package>

Remove a package.

conda remove <package>

Environment variables

List the environment variables.

conda env config vars list

Set an environment variable.

conda env config vars set <variable>=<value>

Unset an environment variable.

conda env config vars unset <variable> --name <env>

Issues

Use Conda in PowerShell.

conda init powershell
Set-ExecutionPolicy RemoteSigned -Scope CurrentUser

PyInstaller

PyInstaller bundles a Python application and all its dependencies into a single package.

Install.

pip install pyinstaller

Usage.

pyinstaller main.py
pyinstaller main.py --onefile