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Python Dates and Times in Python Let's Build a Timed Quiz App Harder Time Machine

Welby Obeng
Welby Obeng
20,340 Points

why TypeError: 'duration' is an invalid keyword argument for this function

why do I get TypeError: 'duration' is an invalid keyword argument for this function for this code

import datetime

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

def time_machine (int, duration):
  if duration == "years":
    int = int * 365
    duration = "days"
  return datetime.timedelta(duration=int)


2 Answers

Hi Welby,

You're getting that error because 'duration' isn't a valid keyword argument for timedelta

duration is a argument that is passed into your time_machine function which holds a string of whatever the time unit was. The valid choices for keyword arguments are : 'days, seconds, microseconds, milliseconds, minutes, hours or weeks'

So when you try to pass in duration as a keyword argument it's interpreting that literally as an argument named duration which isn't in that list.

What you could do is create a dictionary out of the 2 passed in arguments and then unpack that dictionary when passing it into datetime.timedelta

# suppose duration was "days" and int was 5
datetime.timedelta(**{duration:int}) # becomes datetime.timedelta(days=5)

The other problem that you're having is that you're returning the timedelta rather than a new datetime that is the starter time plus the timedelta.

Also, I would recommend not using int for your argument since it's reserved as a data type in python and may cause you problems depending on what you're doing with your code.

Ivan Bodnar
Ivan Bodnar
2,419 Points

Thanks, I had the exact same problem and I couldn't find the answer. I suspected it had to do with unpacking but I didn't know how.

the colour formatting should give you the clue.. int is a special keyword and you shouldnt use it as a variable..

Also i think the problem might be this: return datetime.timedelta(duration=integer) .. you need to pass in the args a different way as far as I remember.. you should create a dict and then pass that in.