List-Data-Validation lost from source file
*Created originally on Bitbucket by [maurermaxnl (Max Maurer)](https://bitbucket.org/%7Bd7279dfa-ebb2-451d-818a-d6d3842f2ba3%7D/)* When plainly opening and saving a file containing a “Data-Validation” of type list and thus producing a nice dropdown in excel like explained here [https://www.techrepublic.com/blog/microsoft-office/how-to-add-a-drop-down-list-to-an-excel-cell/](https://www.techrepublic.com/blog/microsoft-office/how-to-add-a-drop-down-list-to-an-excel-cell/) This cell setting is lost as soon as the file is saved again. \(see attached input and output files\) ### The code used to generate the attached file ```python import openpyxl wb = openpyxl.load_workbook(filename='DropdownTest.xlsx') wb.save('output.xlsx') ``` ### Background In our specific use case this is happening on a sheet in the workbook that we are not even touching/modifying \(as above\). To my current knowledge of the excel format I was wondering why the sheet is rewritten/modified at all if it not even touched by any modification. Wouldn’t it be possible to not touch sheets that never receive a modification? ‌ *Attachments:* [DropdownTest_input.xlsx](/uploads/1aca1c2c92dd89428d941d8ef293454f/DropdownTest_input.xlsx)[DropdownTest_output.xlsx](/uploads/6b95e1562453526ac21866f2e8e8af8b/DropdownTest_output.xlsx)
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