I basically copied the example on DataValidation using openpyxl from the docs (https://openpyxl.readthedocs.io/en/stable/validation.html).
The only difference is that I set the showDropDown arg to True. Unfortunately, this doesn't make any difference, i.e. when I open the Excel sheet, I don't see the dropdown menu. In fact, it has not been enabled at all (compare screenshot).
from openpyxl import Workbook from openpyxl.worksheet.datavalidation import DataValidation # Create the workbook and worksheet we'll be working with wb = Workbook() ws = wb.active # Create a data-validation object with list validation dv = DataValidation( type="list", formula1='"Dog,Cat,Bat"', allow_blank=True, showDropDown=True ) # Optionally set a custom error message dv.error = "Your entry is not in the list" dv.errorTitle = "Invalid Entry" # Optionally set a custom prompt message dv.prompt = "Please select from the list" dv.promptTitle = "List Selection" # Add the data-validation object to the worksheet ws.add_data_validation(dv) dv.add(ws["A1"]) wb.save(filename="dropdown_issue.xlsx") 
