refactor: update colormap API for new versions of matplotlib - #2825
refactor: update colormap API for new versions of matplotlib#2825alepr wants to merge 5 commits into
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Code Review
This pull request introduces a helper function get_colormap in geemap/colormaps.py to unify colormap retrieval across different Matplotlib versions, and refactors geemap/common.py to use it. Feedback suggests that in older Matplotlib versions, plt.colormaps is a function rather than a registry object, which would cause a TypeError when subscripted. It is recommended to check mpl.colormaps instead and gracefully handle cases where cmap_name is already a Colormap instance.
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Pull request overview
This PR continues the Matplotlib colormap API migration by centralizing colormap retrieval in geemap/colormaps.py and refactoring colormap-dependent utilities in geemap/common.py to use that shared helper, aiming to avoid deprecated plt.get_cmap() / plt.cm.get_cmap() patterns.
Changes:
- Add
colormaps.get_colormap()as a centralized colormap accessor with version-dependent fallbacks. - Refactor
save_colorbar()andclassify()to use the centralized colormap accessor. - Make
get_palette_colors()more robust by defaultingNonecolormap names and keeping hex formatting consistent.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.
| File | Description |
|---|---|
| geemap/common.py | Switch colormap lookups in save_colorbar, classify, and get_palette_colors to the new centralized helper; add None fallback for cmap_name. |
| geemap/colormaps.py | Introduce get_colormap() intended to bridge old/new Matplotlib colormap APIs. |
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| cmap_name: The name of the matplotlib colormap. Defaults to None. | ||
| n_class: The number of colors. Defaults to None. | ||
| hashtag: Whether to return a list of hex colors. Defaults to False. | ||
| """ | ||
| try: | ||
| cmap = plt.get_cmap(cmap_name, n_class) | ||
| except: | ||
| cmap = plt.cm.get_cmap(cmap_name, n_class) | ||
| if cmap_name is None: |
Description
Following up on my previous PR (#2822), this PR continue the migration to the updated Matplotlib API for colormap access. Resolves #2499
Previously,
geemaprelied onplt.get_cmap()andplt.cm.get_cmap(), which have been deprecated in newer versions of Matplotlib. To address this and ensure long-term compatibility, I have:get_colormapfunction ingeemap/colormaps.pythat handles the API transition gracefully usinghasattrchecks.common.py(specificallysave_colorbar,classify, andget_palette_colors) to use the new centralized function.get_palette_colorsto handleNonevalues and ensure consistent hex color formatting.This change ensures that
geemapremains compatible with the latest Matplotlib releases while cleaning up deprecated code patterns.