Answer How to convert csv file data using Python_2

The error strptime() arguemnt 1 must be str, not Series appears that change_csv['Date'] is not a string, but Series.

I think you can take the string from Series and process it as shown below.

for index in change_csv['Date'].index:
    dateStr = change_csv['Date'][index]
    date = datetime.strptime(dateStr, '%b %d, %y')
    change_csv['Date'][index] = date.strftime('%Y-%m-%d')