paramtrack

Remembers the arguments of each method's last call, defaults included.

Install

pip install paramtrack

Usage

from paramtrack import track_class

@track_class
class Telescope:
    def observe(self, target, exposure=30, filter="V"):
        ...

telescope = Telescope()
telescope.observe("Vega", exposure=60)

print(telescope.parameters)

observe
├─ target   = 'Vega'
├─ exposure = 60
└─ filter   = 'V'

In Jupyter, put telescope.parameters on the last line of a cell for a foldable view.

Forwarded **kwargs

When a method passes its **kwargs on to another function, the parameters of that function are listed too, defaults included:

def observe(target, exposure=30, filter="V"):
    ...

@track_class
class Telescope:
    def run(self, **kwargs):
        return observe("Vega", **kwargs)

telescope = Telescope()
telescope.run(exposure=60)

print(telescope.parameters)

run
├─ exposure = 60
└─ filter   = 'V'

This works through chains of **kwargs and for calls like self.method(**kwargs) or module.function(**kwargs). The source code has to be available: in a plain python shell, only the passed keywords are shown.

Functions

track_function does the same for plain functions and stores the arguments as function.parameters. Before the first call, it shows the defaults, with ? for arguments that have none:

from paramtrack import track_function

@track_function
def observe(target, exposure=30, filter="V"):
    ...

print(observe.parameters)

observe
├─ target   = ?
├─ exposure = 30
└─ filter   = 'V'

After a call such as observe("Vega"), the values of that call are shown instead.

Development

Run the tests:

uv run pytest

Build the docs into docs/_build/html:

uv run --with-requirements docs/requirements.txt sphinx-build docs docs/_build/html