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

Dave Laffan
Dave Laffan
4,604 Points
Posted by Dave Laffan
Dave Laffan
4,604 Points

Harder Time Machine

Hi. I've already passed this challenge with 

def time_machine(int1, str1):
    if str1 == 'minutes':
        return starter + datetime.timedelta(minutes=int1)
    elif str1 == 'hours':
        return starter + datetime.timedelta(hours=int1)
    elif str1 == 'days':
        return starter + datetime.timedelta(days=int1)
    elif str1 == 'years':
        return starter + datetime.timedelta(days=int1*365)

I've tried simplifying it with

def time_machine(int1, str1):
    return starter + datetime.timedelta(str1=int1)

and that doesn't work. I kind of get why, I think it's because I'm trying to pass a string when it's expecting days/weeks/months - but not sure how to get around this?

I'll know I'll need a quick if/elif for the year, but wanted to simplify the minutes/hours/days somehow?

1 Answer

Wade Williams
Wade Williams
24,476 Points
Wade Williams
Wade Williams
24,476 Points

I like your style, passing something then making it better. What you're looking for is keyword unpacking which you can do with a dictionary.

def time_machine(int1, str1):
    time_dict = {str1: int1}

    if str1 == "years":
        time_dict = {"days": int1*365}

    return starter + datetime.timedelta(**time_dict)

You can also just pass in a dictionary directly into the function as well, which would be really clean if we didn't have to worry about turning "years" into "days".

def time_machine(int1, str1):

    if str1 == "years":
        str1 = "days"
        int1 *= 365

    return starter + datetime.timedelta(**{str1: int1})

Here's a good article on * and ** in function parameters:

http://agiliq.com/blog/2012/06/understanding-args-and-kwargs/

Dave Laffan
Dave Laffan
4,604 Points
Dave Laffan
Dave Laffan
4,604 Points

Hi Wade, really helpful, thank you :)