help me complete this code challenge

I think this is a good place to use eval.

def time_machine(integer, string):
    if string == 'years':
        integer *= 365
        string = "days"
    return starter + eval("datetime.timedelta({}=integer)".format(string))

My apologies. I was trying to match up the days when I changed the years. I got the code to work by removing the + 1 and by changing 'year' to 'years'.

A simple solution for this problem is to first check if the string is 'years' and if so change the string to 'days' since timedelta will not except years as an argument. Then multiply the integer by 365 to get the equivalent number of days for the given number of years. Finally, return the duration as the difference of the starter datetime and the timedelta of the string and integer passed to the method as a literal dictionary with the ** prefix operator to unpack the dictionary.

import datetime

starter = datetime.datetime(2015, 10, 21, 16, 29)

def time_machine(integer, string):
    if string == 'years':
        string = 'days'
        integer *= 365
    return starter + datetime.timedelta(**{string: integer})

You can't do timedelta(year=9). So you have to make a year. Years are made up of days, so how would you go from a provided number, like 9, and the attribute days, to get 9 years? Remember, years should just be considered as 365 days.

Kenneth this is the code that I got which outputs all of the correct timedeltas, even the years. But for some reason I am not Code Challenge is not accepting the answer. Can you give me a further hint on what I am doing wrong? Thanks!

import datetime

starter = datetime.datetime(2015, 10, 21, 16, 29)

# Remember, you can't set "years" on a timedelta!
# Consider a year to be 365 days.

## Example
# time_machine(5, "minutes") => datetime(2015, 10, 21, 16, 34)

def time_machine(integer,string):
  if string == 'hours' :
    return starter + datetime.timedelta(hours = integer)
  elif string == 'days' :
    return starter + datetime.timedelta(days = integer)
  elif string == 'year' :
    return starter + datetime.timedelta(days = integer * 365 + 1)
  elif string == 'minutes' :
    return starter + datetime.timedelta(minutes = integer)