openpyxl\compat\__init__.py:depreciated() contains this at line 48:
This seems like a bad idea as it means there is no way to suppress DeprecationWarnings. The problem is that openpyxl itself raises DepreciationWarnings, which the user can't avoid:
...\openpyxl\worksheet\read_only.py:189: DeprecationWarning: Call to deprecated function get_squared_range (Use ws.iter_rows()).
then this means your stdout gets trashed without being able to do anything about it :-(. Overriding any filter added by client code doesn't seem like very good practice?