Question

I wrote a python script that takes a csv which has dates in an M/D/YYYY format, then matches them with dates in an xlwt generated .xls file. I was wondering why only some dates are matched and then I noticed that the only dates that were matched were strings that were 10 characters long (11/14/2011) and dates that were not 10 characters long (1/14/2011 or 1/7/2012) were not matched. How do I get the csv file to save the dates in 10 character long strings? Or should I convert the csv file into a txt file?

Answer 1

csv doesn’t know anything about dates; it just reads text. You are comparing strings with other strings, and '1/7/2012' and '01/07/2012' are different strings altogether.

You’d need to parse the dates into something that can be compared, when reading. Use the datetime.datetime.strptime() function for that:

import datetime

dt = datetime.datetime.strptime(datecolumn, '%m/%d/%Y').date()

The strptime() format above would turn both 1/7/2012 and 01/07/2012 into a datetime.date(2012, 1, 7), and two copies of that date() instance would compare as equal.