Age from birthdate in python

That can be done much simpler considering that int(True) is 1 and int(False) is 0, and tuples comparison goes from left to right:

from datetime import date

def calculate_age(born):
    today = date.today()
    return today.year - born.year - ((today.month, today.day) < (born.month, born.day))

from datetime import date

def calculate_age(born):
    today = date.today()
    try: 
        birthday = born.replace(year=today.year)
    except ValueError: # raised when birth date is February 29 and the current year is not a leap year
        birthday = born.replace(year=today.year, month=born.month+1, day=1)
    if birthday > today:
        return today.year - born.year - 1
    else:
        return today.year - born.year

Update: Use Danny's solution, it's better

from datetime import date

days_in_year = 365.2425    
age = int((date.today() - birth_date).days / days_in_year)

In Python 3, you could perform division on datetime.timedelta:

from datetime import date, timedelta

age = (date.today() - birth_date) // timedelta(days=365.2425)

The simplest way is using python-dateutil

import datetime

import dateutil

def birthday(date):
    # Get the current date
    now = datetime.datetime.utcnow()
    now = now.date()

    # Get the difference between the current date and the birthday
    age = dateutil.relativedelta.relativedelta(now, date)
    age = age.years

    return age