VenvFreezer

Creates a Python 3 venv from a given requirements.txt file and stores the exact version of each installed package, for later recreation of the venv, in a requirements.freeze file. It can also download all dependencies for a later offline build or a faster recreation of the venv.

Features

Uses Python 3 venv! No need to install virtualenv.
Supports offline builds! Using pip wheels, pip download and pip --find-links.
Reliable and deterministic! It creates a requirements.freeze file with the exact version of each package like pip freeze.
Fast! It only recreates the venv when the requirements.freeze has changed.
Windows, Linux and MacOSX are supported.

Installation

Just download venvfreezer.py into your project folder where the requirements.txt is.

$ wget https://raw.githubusercontent.com/trunneml/venvfreezer/master/venvfreezer.py

Or checkout out this repository and run:

$ pip install .

Usage

Switch into your project folder and run:

$ python3 -m venvfreezer

VenvFreezer will create a venv in the folder venv and install all requirements form your requirements.txt and requirements.*.txt files.

VenvFreezer also creates a requirements.freeze file with the exact versions of your requirements (like php composer or npm packages). The next time you create your venv VenvFreezer will use this requirements.freeze file to recreate a venv with the same versions as before. You can commit this file to save the tested versions of your requirements without messing up your requirements.txt. This also ensures that each developer in your team uses the same dependencies and versions in development.

To reduce build time VenvFreezer also checks if your requirements.freeze has changed between two VenvFreezer runs. It will not recreate the venv when nothing has changed. This way you can run VenvFreezer after every git pull without wasting build time if nothing has changed on your requirements. If you still want to recreate the venv just delete the folder (rm -Rf venv) and rerun python venvfreezer.

You can also download the dependencies for a later offline build or to save network bandwidth by running:

$ python3 -m venvfreezer download

This command creates a new folder ./requirements that contains all packages (for the current OS) from the requirements.freeze file. VenvFreezer uses this folder as a cache for the next venv creation.

For more information run:

$ python3 -m venvfreezer --help

Requirements

Python >= 3.4
venv (Standard Python lib)
Linux, Windows or MacOSX

Hint: Under Debian and Ubuntu the standard venv lib must be installed seperate by running:

$ sudo apt-get install python3-venv

TODOs

Detect vagrant and change venv path
Add upgrade command
Upload to pypi

trunneml / venvfreezer