Defused CSV

defusedcsv is a Python library (version 3.0.0) that acts as a drop-in replacement for the standard library's `csv` module, specifically designed to mitigate CSV injection attacks. It works by sanitizing output, prepending an apostrophe to cells that start with potentially malicious characters like `=`, `+`, `-`, `@`, `|`, or `%`, and escaping `|` characters within these cells. This prevents spreadsheet software (like MS Excel or LibreOffice) from interpreting the cell content as a formula. The library's release cadence appears to be infrequent, with the latest version published to PyPI on September 2, 2025.