Add default month/day to known year in new date field?

Question

I have a text field featuring a 4 digit year. How would I assign a default month and day to the year in a new date field?

ex. 2010 needs to be converted to 1/1/2010

I attempted this in the field calculator:

def dt(year):
    dt_str = year
    dt_obj = datetime.datetime.strptime(dt_str, '%Y')
    return dt_obj

install date =

dt(!year!)

Answer 1

Change the function name to ensure it's not overloading date from datetime, or overloading a common short version of the datetime module (dt). Make sure you are importing datetime within the codeblock.

import datetime
def extractdate(year):
    #may need to change to str(year) if your input column is numeric
    #year = str(year)
    dt_obj = datetime.datetime.strptime(year, '%Y')
    return dt_obj

By default it will use January 1st, but if you want to control the month or date you can add more to the string and convert via strptime.

e.g. dt_obj = datetime.datetime.strptime(year+'03', '%Y%m') would give you all March 1st dates.