Using Python 3 please modify this script replacing the comments with code to print future and past dates. I have already configured the def (after) string. 

Script(Please show output of script)

#!/usr/bin/env python3

import sys

def usage():
   """Prints usage information for the script."""
  print("Usage: python dbda.py YYYY-MM-DD [days]")
  print("Given a start date and a number of days into the past/future, give date")

 

def valid_date(date: str) -> bool:
   "TODO enter docstring"
   # return True or False
   pass # TODO: delete this line, replace with valid code.

 

def leap_year(year: int) -> bool:
   "takes a year in YYYY format, and returns True if it's a leap year, False otherwise."
   # TODO reorganize code, enter code from after() here.
   pass # TODO: delete this line, replace with return statement.

def after(date: str) -> str:
   "after takes a valid date string in YYYY format and returns"
   "a date string for the next day in YYYY-MM-DD format."
   if len(date) != 10:
       return '0000-00-00'
   else:
       str_year, str_month, str_day = date.split('-')
       year = int(str_year)
       month = int(str_month)
       day = int(str_day)

       lyear = year % 4 # TODO: put this into the function leap_year.
       if lyear == 0:
           feb_max = 29
       else:
           feb_max = 28

       lyear = year % 100
       if lyear == 0:
           feb_max = 28

       lyear = year % 400
       if lyear == 0:
           feb_max = 29

       tmp_day = day + 1

       mon_max = { 1:31, 2:feb_max, 3:31, 4:30, 5:31, 6:30, 7:31, 8:31, 9:30, 10:31, 11:30, 12:31}
       if tmp_day > mon_max[month]:
           to_day = tmp_day % mon_max[month] # if tmp_day > this month's max, reset to 1
           tmp_month = month + 1
       else:
           to_day = tmp_day
           tmp_month = month + 0

       if tmp_month > 12:
           to_month = 1
           year = year + 1
       else:
           to_month = tmp_month + 0

       next_date = f"{year}-{to_month:02}-{to_day:02}"
       return next_date

 

def before(date: str) -> str:
   "TODO enter docstring."
   pass # TODO replace this with code, using your algorithm document.

 

def dbda(start_date: str, step: int) -> str:
   "given a start date and a number of days into the past/future, give date"
   # make a loop
   # call before() or after() as appropriate
   # return the date as a string YYYY-MM-DD
   pass

 

if __name__ == "__main__":
   # process command line arguments
   # call dbda()
   # output the result
   pass