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MF001: general-formatting

✨ Formatting 🛠️ Fixable

MF001: General formatting issues with the notebook format.

What it does

Examines the notebook serialization for structural violations such as: - Missing or incorrect marimo import statements - Improperly formatted cell definitions - Missing app initialization code - Incorrect file generation metadata

Why is this bad?

Format violations can prevent marimo from properly loading or executing notebooks. While these don't affect the Python code logic, formatting errors mark a deviation in the expected script structure, which can lead to unexpected behavior when run as a script, or when loading the notebook.

Examples

Problematic: 

# Missing marimo import
@app.cell
def __():
    return


if __name__ == "__main__":
    app.run()

Solution: 

import marimo

__generated_with = "0.1.0"
app = marimo.App()


@app.cell
def __():
    return


if __name__ == "__main__":
    app.run()

Note: Most format issues are automatically fixable with marimo check --fix.

References