Using Python to Insert Filename into Column

Using Python to Insert Filename into Column

I have  a folder full of two-column  excel files. Column A has  attributes, Column B has values. I want to loop through the folder and insert a row at the top of the worksheet ("Sheet1")
and enter the values "Filename" in column A and  the actual filename in Column B (without the full path, just the file name). I have tried  creating two data frames, using concat, but has not worked.  Please  advise.