steps-widget

Jupyter widget and CLI that trace Python expression evaluation step by step.

• %%steps -- a cell magic (registered by import steps_widget) that renders the substitution/reduction trace of any # PRINT STEPS-tagged statement as a widget below the cell.
• print-steps -- the command-line equivalent: print-steps student_script.py prints the same trace to stderr for every tagged line in a script.

Tag convention: append # PRINT STEPS (or #PRINT-STEPS, # printsteps, ... -- see steps_widget.print_steps._COMMENT_TAGS for every recognized spelling) to a statement to have it evaluated one operation at a time instead of all at once.

import steps_widget

%%steps
x = 7
y = 5
z = x * y + 4  # PRINT STEPS

Requires Python 3.10 through 3.13 -- the stepper dispatches on CPython bytecode opcode names, which change across these versions; each is handled by its own dispatch table (see CLAUDE.md).

pip install steps-widget
# or
conda install -c munch-group steps-widget

See the docs for more.

Initial set up

pixi run init

Get updates to upstream fork

Add upstream if not already added

git remote add upstream https://github.com/munch-group/steps-widget.git

Fetch upstream changes

git fetch upstream

Either rebase your changes on top of upstream (cleaner history)

git rebase upstream/main

Or, merge upstream into your fork (preserves history)

git merge upstream/main

If you want to see what's changed upstream before applying:

git log HEAD..upstream/main

See the actual diff

git diff HEAD...upstream/main

Then push your updated fork:

git push origin main

If you rebased and need to force push

git push origin main --force-with-lease