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Static type checkers can't recognize colormaps

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
45/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
data-visualization

Research direction

Inspect cmocean/cm.py and the cmap_d definition to see how colormaps are created dynamically. Compare the referenced Matplotlib cm.pyi stub and determine how a generated stub would expose the colormap attributes and types; done means MyPy and Pylance recognize entries such as cmocean.cm.balance.

Written by the indexing model from the issue text.

Description

Static type checkers like MyPy or Pylance can't recognize variables created dynamically with locals().update(cmap_d). Past just type checking, Pylance can't even recognize that colormaps exist, e.g., cmocean.cm.balance produces an attribute access issue error in Pylance.

Matplotlib colormaps have the same issue, which they solve by including a stub file cm.pyi that defines the attributes and types.

If there's interest in include a cm.pyi file here, it is straightforward to generate one automatically based on the colormaps defined in cmap_d and I'd be happy to make a PR with the details.

Dominant language
Python
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Forks
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