topic Re: Calculate age function in Python Questions

Calculate age function

mpboyle — Wed, 30 Sep 2015 15:43:48 GMT

Does anyone have a python code block that calculates age based on a date field within a table? I have tried a few different things but to no success. Was wondering if someone has successfully done this?

Thanks!

Re: Calculate age function

JamesCrandall — Wed, 30 Sep 2015 15:50:43 GMT

Use a timedelta. It should work for seconds, days, weeks, months, years, etc... Easiest example I found is below. Just get your minimum and maximum dates in the field/table and determine the difference.

http://stackoverflow.com/questions/1345827/how-do-i-find-the-time-difference-between-two-datetime-objects-in-python

Re: Calculate age function

JakeSkinner — Sat, 11 Dec 2021 19:02:09 GMT

Hi Matthew,

Here is one option using the field calculator. The below example worked when I had the date in the format: 8/15/2010.

from datetime import datetime

def calculate_age(born):
    today = date.today()
    bornDate =datetime.strptime(born, '%m/%d/%Y')
    return today.year - bornDate.year - ((today.month, today.day) < (bornDate.month, bornDate.day))

Re: Calculate age function

mpboyle — Sat, 11 Dec 2021 19:02:12 GMT

James,

If I try finding the difference between today's date and the date in my field, I get an error: unsupported operand type(s) for: 'datetime.date' and 'unicode'. Is there a way to format the date field to something other than unicode?

Below is the function I have now. The field I'm passing in for 'bday' is a Date field within a file gdb.

import datetime

def calcAge(bday):
  today = datetime.date.today()
  diff = today - bday
  return diff

Re: Calculate age function

mpboyle — Wed, 30 Sep 2015 16:17:39 GMT

Jake Skinner,

When I try your method, I get an error: 'global name 'date' is not defined'.

Re: Calculate age function

DarrenWiens2 — Wed, 30 Sep 2015 16:35:44 GMT

I know this is in the Python section, but if all you need is number of days, VBScript handles it much easier (below is for shapefile, but should work similarly for GDB):

Now (  ) - [YOURDATE]

or years:

CInt((Now (  ) - [YOURDATE])/365)

Re: Calculate age function

JakeSkinner — Sat, 11 Dec 2021 19:02:14 GMT

Try replacing the today variable with 'today = datetime.now( )'. Ex:

from datetime import datetime

def calculate_age(born):
    today = datetime.now( )
    bornDate =datetime.strptime(born, '%m/%d/%Y')
    return today.year - bornDate.year - ((today.month, today.day) < (bornDate.month, bornDate.day))

Re: Calculate age function

JamesCrandall — Wed, 30 Sep 2015 17:31:25 GMT

Welcome to the wonderful world of date manipulation!

I think Jake has your answer below.

Re: Calculate age function

mpboyle — Wed, 30 Sep 2015 17:42:33 GMT

Thanks Jake Skinner! This worked