Fix EmptyDataError when reading empty CSV files#995
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benoit-cty merged 2 commits intomlco2:masterfrom Dec 28, 2025
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If we changed line 90 from to something like then I think we could rely on the existing logic without adding more conditionals? Personally I already find the existing logic hard to follow. |
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good idea, done |
Handle pandas.errors.EmptyDataError that occurs when pd.read_csv() encounters an existing but empty CSV file. This fix catches the error in both 'append' and 'update' modes and treats the empty file as if it doesn't exist, creating a new file with the current data. The fix prevents crashes when emission CSV files exist but are empty, which can happen if a previous write operation was interrupted. Added test cases for both append and update modes with empty files.
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Thanks a lot and sorry for the delay !
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Description
This PR fixes a bug where
pandas.errors.EmptyDataErroris raised when the FileOutput class attempts to read an existing but empty CSV file. The fix adds error handling in theout()method to catch this exception and treat empty files as if they don't exist, creating a new file with the current emissions data.Related Issue
I have not opened an issue.
Motivation and Context
This bug occurs when CSV emission files exist but are empty, which can happen if:
Without this fix, the application crashes with
pandas.errors.EmptyDataError: No columns to parse from filewhen trying to append or update emissions data, preventing users from tracking their carbon emissions.How Has This Been Tested?
Unit Tests: Added two new test cases in
tests/output_methods/test_file.py:test_file_output_out_append_empty_file_exists(): Verifies append mode handles empty files correctlytest_file_output_out_update_empty_file_exists(): Verifies update mode handles empty files correctlyManual Testing:
Pre-commit Hooks: Ran all linting and formatting checks
Test Suite: Ran the full test suite to ensure no regressions:
Screenshots (if appropriate):
N/A - This is a bug fix with no UI changes
Types of changes
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