rules_python_interactive

This module makes it easy to start a Python shell (with tab completition!)¹ which can import modules from py_library targets for easier debugging. What it does is similar to what the REPL feature in rules_python does, but for some, perhaps more ergonomically. Importantly, if you commonly need a Python shell for debugging, rules_python_interactive makes starting one as easy as running a Bazel target.

Setup

Modify your MODULE.bazel file to load rules_python_interactive. For example:

bazel_dep(name = "rules_python_interactive", version = "0.1.1")

git_override(
    module_name = "rules_python_interactive",
    remote = "https://github.com/jpwoodbu/rules_python_interactive.git",
    branch = "main",
)

Modify a BUILD.bazel file to use py_interactive:

load("@rules_python_interactive//python:defs.bzl", "py_interactive")

# one or more py_library rules of your own here...

py_interactive(
    name = "my_library_interactive",  # This can be any name you like.
    deps = [":my_library"],
)

Note that py_interactive wraps py_binary, so any argument py_binary takes can also be passed to py_interactive with the exception of srcs, main, and args.

Usage

Run the py_interactive target:

$ bazel run :my_library_interactive
INFO: Analyzed target //:my_library_interactive (80 packages loaded, 3454 targets configured).
INFO: Found 1 target...
Target //:my_library_interactive up-to-date:
  bazel-bin/my_library_interactive
INFO: Elapsed time: 0.534s, Critical Path: 0.00s
INFO: 1 process: 5 action cache hit, 1 internal.
INFO: Build completed successfully, 1 total action
Bazel py_interactive ready.
>>> import my_library
>>> my_library.foo()
We are fooing!!!

Pushes argument

If there is some setup you'd like run in the Python shell at start up, e.g. importing your library, you can add arbitrary Python statements to run on the shell using the pushes argument for the py_interactive macro. They will be run in order and with no error handling. If a statement produces an error, it is ignored and any further statements will still be attempted.

For example:

py_interactive(
    name = "my_library_interactive",
    deps = [":my_library"],
    pushes = [
        "import my_library",
        "my_library.do_some_set_up()",
    ]
)

Custom repo name

When modifying your MODULE.bazel file, if you passed a repo_name argument to bazel_dep, then you must also pass the same repo_name value to each py_interactive target. This is due to the macro needing to make a reference to a Python script inside the rules_python_interactive module used to start the Python shell.

For example:

MODULE.bazel

bazel_dep(name = "rules_python_interactive", version = "0.1.1", repo_name="some_other_repo_name")

BUILD.bazel

py_interactive(
    name = "my_library_interactive",
    deps = [":my_library"],
    repo_name = "some_other_repo_name",
)

Footnotes

1. Tab completion only works on supported platforms, which are the platforms where GNU readline is available. ↩