UMR-CNRM/EPyGrAM — reverse-engineered prompt

Build me a Python library for working with meteorological field data, similar to a toolkit scientists could install and use from scripts or the command line.

It should let users open weather field files, inspect the fields inside them, analyze them, and make basic graphics like plotting a selected field on a map. It should support multiple file formats where possible, but if an optional format dependency is missing, that format should just be disabled instead of breaking the whole package.

Please set it up as a proper installable Python package with optional extras for things like graphics, docs, extra features, and extra formats. Include command line tools under one main command called epygram with subcommands, plus simple aliases like epy_cartoplot for plotting a field from a file.

Add Sphinx documentation generation, a Makefile target for docs, tests with a short test README, and packaging metadata so it can be installed with pip. Look up current Python packaging docs online if needed.