pyenv-mkenv

Simplify pyenv environment creation; script requires python 3.6+.

Do you use pyenv?

When you check out a new repository, the workflow looks something like this:

pyenv virtualenv $MY_PY_VERSION $MY_REPO_NAME
pyenv local $MY_REPO_NAME
pip install -U pip
pip install -r requirements.txt

There has to be a better way!

Now there is:

mkenv -r requirements.txt

This script does a number of things:

• Pick a python version (by preference, the most recent installed CPython version; see below)
• Create a pyenv-virtualenv using the directory name by default (controlled by -n / --name)
• Update pip
• Install requirements (multiple paths can be given)

Installation

• From PyPI: pip install pyenv-mkenv
• From github: pip install git+git://github.com/clbarnes/pyenv-mkenv.git
• For development: git clone git@github.com:clbarnes/pyenv-mkenv.git && cd pyenv-mkenv && pip install -e .

Or just copy mkenv.py; it's dependency-free.

Usage

usage: mkenv [-h] [-p] [-n NAME] [-r [REQUIREMENTS]] [-v] [--version]
             [py_version]

positional arguments:
  py_version            Python version. If this option starts with '/', the
                        rest will be interpreted as a regex; otherwise, a
                        simple match to the start of the version name will be
                        used. Empty string by default. By default, mkenv will
                        try to find the highest version matching the string
                        (use -p to see priority and pick) manually)

optional arguments:
  -h, --help            show this help message and exit
  -p, --pick            Prompt to select from matching versions
  -n NAME, --name NAME  Name for the environment (defaults to directory name)
  -r [REQUIREMENTS], --requirements [REQUIREMENTS]
                        Requirements files to install from. If option is used
                        with no path given, user will be prompted.
  -v, --verbose
  --version             show program's version number and exit

Python version

pyenv-mkenv lists available python versions (i.e. non-symlink directories in $PYENV_HOME/versions/), and sorts them. The sort order is intended to be somewhat intuitive:

• Prefer standard CPython distributions (i.e. starts with a digit)
• Prefer higher versions (i.e. substrings which look like versions are parsed and sorted descending)
• Non-standard distributions are sorted lexicographically without version numbers, and then by their version number (multiple version numbers, e.g. pypy3.6-7.3.0, are addressed left to right)

If no py_version argument is given, the first item on the list is chosen. If a string is given, the first item on the list which starts with that string is chosen (e.g. 3.8 -> 3.8.1). If the given string starts with a /, treat the remainder as a regex which is searched for within each version name; the first matching name is used.

To make sure which version you're getting, use the -p / --pick option. This will show versions which match the py_version argument (in sorted order), and allow you to select which one you want.

Requirements

By default, mkenv does not install any requirements. However, any number of requirements files can be added by using the -r option. If -r is supplied without an argument, mkenv searches down into the directory tree, looking for anything matching the glob requirements*.txt, ignoring hidden directories, and prompts the user to select which ones they want to install.

Disclaimer

This is not a pyenv plugin; it is a python script which assumes you have pyenv installed.