how to convert a string date into datetime format in python? [duplicate]

The particular format for strptime:

datetime.datetime.strptime(string_date, "%Y-%m-%d %H:%M:%S.%f")
#>>> datetime.datetime(2013, 9, 28, 20, 30, 55, 782000)

You should use datetime.datetime.strptime:

import datetime

dt = datetime.datetime.strptime(string_date, fmt)

fmt will need to be the appropriate format for your string. You'll find the reference on how to build your format here.