Pandas Excel Writer using Openpyxl with existing workbook
In the source code of ExcelWriter, with openpyxl, it initializes empty workbook and delete all sheets. That's why you need to add it explicitly
class _OpenpyxlWriter(ExcelWriter): engine = 'openpyxl' supported_extensions = ('.xlsx', '.xlsm') def __init__(self, path, engine=None, **engine_kwargs): # Use the openpyxl module as the Excel writer. from openpyxl.workbook import Workbook super(_OpenpyxlWriter, self).__init__(path, **engine_kwargs) # Create workbook object with default optimized_write=True. self.book = Workbook() # Openpyxl 1.6.1 adds a dummy sheet. We remove it. if self.book.worksheets: try: self.book.remove(self.book.worksheets[0]) except AttributeError: # compat self.book.remove_sheet(self.book.worksheets[0])