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

Jordan Bester
Jordan Bester
4,752 Points
Posted by Jordan Bester
Jordan Bester
4,752 Points

Write a function named time_machine that takes an integer and a string of "minutes", "hours", "days", or "years".

Completely confused on this one? any help on how to solve?

time_machine.py 
import datetime
from datetime import timedelta

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

def time_machine(1=minutes, 2=hours, 4=days, 1=years):
  return time_machine(
# 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)

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

Stepping through the challenge

# Write a function named `time_machine` that takes an integer and a string..
def time_machine(num, string):
    '''string is one of "minutes", "hours", "days", or "years".
    num is multiple of this unit.
    '''
    # check for each string value and generate the appropriate timedelta
    if string == 'minutes':
        delta = datetime.timedelta(minutes=num)
    if string == 'hours':
        delta = datetime.timedelta(hours=num)
    if string == 'days':
        delta = datetime.timedelta(days=num)
    if string == 'years':
        num = num * 365
        delta = datetime.timedelta(days=num)
    # add this delta to 'starter' and return
    return starter + delta

This can be compresses by building a dictionary of arguments for timedelta:

# Write a function named `time_machine` that takes an integer and a string..
def time_machine(num, string):
    '''string is one of "minutes", "hours", "days", or "years".
    num is multiple of this unit.
    '''
    # adjust num if string is 'years'
    if string == 'years':
        num = num * 365
        # change string to 'days'
        string = 'days'
    # build keyword args
    kwargs = {string: num}
    # create timedelta
    delta = datetime.timedelta(**kwargs)
    # add this delta to 'starter' and return
    return starter + delta

Compressing further to get:

import datetime

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

def time_machine(value, units):
    if units == "years":
        value *= 365
        units = "days"
    return starter + datetime.timedelta(**{units: value})