sorry am new here and a total Python Rookie.

I pull Data with Python from Jira and put it into DataFrame. There I have a datetime as string in following format: DD/MM/YY HH:MM AM (or PM). Now I want to convert to Datetime to make it comparable with other datetimes to DD/MM/YY HH:MM:SS. I wanted to use datetime.strptime but it always fails. Any ideas? Thanks in advance!