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Python Dates and Times in Python (2014) Let's Build a Timed Quiz App Harder Time Machine

Posted by Brad Pettigrew
Brad Pettigrew
1,834 Points

Argument format for timedelta

Hey I'm running into a bit of trouble with one of the python track challenges. I'm trying to take a string (time) and an int variable (length of time) and return a timedelta equivalent to the two. E.g. time = days, int = 5, return timedelta(days=5). However, I have trouble simply plugging the variables into the timedelta function. If I do not convert my integer to a string, python says it cannot implicitly convert int to str, but if I convert to string, python says the timedelta function does not take str input. So how should I input my string and integer into the timedelta function?

time_machine.py 
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(int, time):
  if time == "years":
    int *= 365
    time = "days"
  return starter + datetime.timedelta(time + "=" + int)

1 Answer

Hanley Chan
Hanley Chan
27,771 Points
Hanley Chan
Hanley Chan
27,771 Points

Hi

This should work. I put your time and integer into a dictionary.

  return starter + datetime.timedelta(**{time: int})
Bryan Manhollan
Bryan Manhollan
Courses Plus Student 9,608 Points
Bryan Manhollan
Bryan Manhollan
Courses Plus Student 9,608 Points

Glad this was here because I would have never thought of doing it this way. :)

Could anyone tell me why time=num portion doesn't work in the return? I kept getting a "time is an invalid keyword argument for this function". Not sure why the string will manually set in this manner but won't set if used as a variable.

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(num, time):
  if time == "years":
    num *= 365
    time = "days"
  return starter + datetime.timedelta(time=num)