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Selectively sync packages

Now that we've got a combination of plain and categorized dependencies, we may wish to sync our venv state to match either or both:

[venv] % pips requirements.txt      # install regular deps, uninstall others
[venv] % pips dev-requirements.txt  # install dev deps, uninstall others
[venv] % pips dev-requirements.txt requirements.txt  # install multiple dep groups
[venv] % pips                       # install all dep groups

You may also use envin as a drop-in replacement for pips in the above examples, which will both activate a venv (creating it if necessary) and sync according to all or specified lockfiles.

pipc and pipcs deal with dependency groups the same way, as zero or more file arguments, but expect the respective requirements.in files rather than the requirements.txt lockfiles.

activate vs envin

The functions activate (alias a8) and envin are similar; each one activates a venv for your current shell, first creating it if necessary.

If you were to use envin at the beginning of these docs rather than activate, your system would be in exactly the same state.

So how do they differ?

The Project Folder

  • envin always operates on a venv associated with the current folder
  • activate uses the current folder by default, but also accepts a project path argument, or -i to select the project folder interactively

Existing Venv Behavior

  • envin always syncs the venv according to requirements.txt files
  • activate only syncs when creating a new venv; otherwise, it's activated as-is

Dependency Groups

In other words

<category>-requirements.txt

  • activate, when syncing at all, always syncs according to all requirements.txt files
  • envin syncs according to all requirements.txt files by default, but also accepts any number of lockfile arguments, just like pips

Deactivation

These are standard Python virtual environments, and so can be deactivated with:

[venv] % deactivate

For symmetry with a8 and envin, zpy adds two aliases for the same command: da8 and envout.

% zpy help pips activate envin

# Install packages according to all found or specified requirements.txt files (sync).
pips [<reqs-txt>...]

# Activate the venv for the current folder or specified project, if it exists.
# Otherwise create, activate, sync.
# Pass -i to interactively choose the project.
# Pass --py to use another interpreter and named venv.
activate [--py pypy|current] [-i|<proj-dir>]

# Activate the venv (creating if needed) for the current folder, and sync
# its installed package set according to all found or specified requirements.txt files.
# In other words: [create, ]activate, sync.
# The interpreter will be whatever 'python3' refers to at time of venv creation, by default.
# Pass --py to use another interpreter and named venv.
envin [--py pypy|current] [<reqs-txt>...]