venv-create permalink

Create virtual environments from a yaml or toml config file and install extra dependencies. To speed things up, the pipeline creates multiple venvs concurrently in parallel.

This pipeline uses the pypyr.steps.venv step under the covers, so check the step’s documentation for further detail on the config inputs.

This pipeline creates Python stdlib virtual environments (venv) from declarative config without writing any script yourself. The underlying mechanism is pretty much the equivalent of $ python -m venv my-dir.

You can run this pipeline in two ways:

ad hoc yaml input permalink

You can run the venv-create pipepeline with an arbitrary yaml file as input like this:

$ pypyr venv-create ~/my-dir/my-venvs.yaml

The file ~/my-dir/my-venvs.yaml looks like this:

  - path: ~/.venvs/python-dev
    pip: autopep8 flake8==5.0.4 pylint rstcheck pygments rope
    clear: True

  - path: # 2 venvs with the same settings
      - ~/.venvs/myproj-dev
      - /another-dir/my-venv
    pip: -e ~/git/myp-proj/my-repo[dev] tox mypy types-python-dateutil

  - path: ~/.venvs/aws-cli
    pip: awscli
    clear: True

  - path: ~/.venvs/pygments
    pip: pygments
    clear: True

When you run $ pypyr venv-create ~/my-dir/my-venvs.yaml pypyr will create all the environments under venv in parallel, and once that’s done run the pip installs sequentially.

If you just want a venv with defaults and no extra options, you can simplify the input to:

# ~/my-dir/my-venvs.yaml
  - my-dir/venv1
  - my-dir/venv2
  - another-dir/another-venv

The venv key can co-exist with other top-level keys in your yaml config file.

When you pass a path to the venv-create pipeline from the cli pypyr will not look for the vars.venv key in pypyr config (see next section).

config permalink

Alternatively, you can keep your venv setup settings in one of pypyr’s config files. In this case you do not need to pass a path to the venv-create pipeline and just run it like this:

$ pypyr venv-create

Here pypyr will look for a venv key in one of these files:

  • pyproject.toml in current dir, under the [tool.pypyr.vars] table
  • or under the vars key in any of the pypyr yaml config files:
    • ./pypyr-config.yaml
    • {user config dir}/pypyr/config.yaml
    • {global config dirs}/pypyr/config.yaml

Remember that pypyr merges config settings from all available config sources, so you can for example specify globally applicable venvs in the global file, user applicable venvs in the user file and local values in ./pyproject.toml and ./pypyr-config.yaml. When you run $ pypyr venv-create it will create all the venvs specified by the combined effective config.

See pypyr configuration for details on pypyr configuration file locations, loading order and formats.

When you run $ pypyr venv-create pypyr will create all the environments under vars.venv in parallel, and once this is done run the specified pip installs sequentially.

pyproject.toml permalink

You can create multiple venvs in parallel by specifying your config settings in pyproject.toml like this:

venv = [
  {path = "my-dir/env2", pip = "tox pytest", quiet = true},
  {path = ["my-dir/env3-1", "another-dir/env3-2"], pip = "cowsay pypyr", quiet = true},

The bare string list entries will create a default venv with no custom options.

The nested table allows you to specify extra custom options for your venv. Note that you can create multiple venvs with the same custom options by passing a list of paths to path.

If you prefer using toml’s array of tables syntax, that would look like this:

path = "my-dir/env1"
pip = "coverage black>=1.2.3"
quiet = true

path = "another-dir/env2"
pip = "tox pytest"
upgrade_pip = false

If you just want to create one venv with no custom options, you can simplify your input like this:

venv = "~/my-dir/myvenv"

If you just want to create one venv with custom options:

path = "~/my-dir/myvenv"
pip = "cowsay pytest tox"
quiet = true

To create all the specified venvs from the combined effective config, from the directory containing your pyproject.toml run:

$ pypyr venv-create

yaml config permalink

Have a vars->venv key in any of the pypyr yaml config files:

# ./pypyr-config.yaml
    - path: ~/.venvs/python-dev
      pip: autopep8 flake8 pylint rstcheck pygments rope
      clear: True

    - path: ~/.venvs/pypyr-dev
      pip: -e ~/git/pypyr/pypyr[dev] tox mypy types-python-dateutil

config format permalink

You can use any of the custom venv creation options documented here. You only need to specify an optional input if you want to over-ride the default value.

  path: mydir/my-venv
  pip: cowsay pypyr
  quiet: False
  system_site_packages: False
  clear: False
  symlinks: True # default True on posix; False on windows
  upgrade: False
  with_pip: True
  upgrade_pip: True
  prompt: None

The toml and yaml formats both use the same inputs and are structurally equivalent, so it’s just the syntax that differs.

Be careful about not using an absolute path as a value for path. Remember that if you use a relative path the venv will create relative to whatever directory you’re in currently.

If you want to create multiple venvs with the same settings, you can pass a list of paths to path:

    - .venvs/venv1
    - /another-dir/another-env
  pip: cowsay pypyr
  clear: True
  quiet: True
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