Seasons of Love

Five hundred twenty-five thousand, six hundred minutes
Five hundred twenty-five thousand moments so dear
Five hundred twenty-five thousand, six hundred minutes
How do you measure, measure a year?

— “Seasons of Love,” Rent

Assuming there are 365 days in a year, there are $365 \times 24 \times 60 = 525,600$ minutes in that same year (because there are 24 hours in a day and 60 minutes in an hour). But how many minutes are there in two or more years? Well, it depends on how many of those are leap years with 366 days, per the Gregorian calendar, as some of them could have $1 \times 24 \times 60 = 1,440$ additional minutes. In fact, how many minutes has it been since you were born? Well, that, too, depends on how many leap years there have been since! There is an algorithm for such, but let’s not reinvent that wheel. Let’s use a library instead. Fortunately, Python comes with a datetime module that has a class called date that can help, per docs.python.org/3/library/datetime.html#date-objects.

In a file called seasons.py, implement a program that prompts the user for their date of birth in YYYY-MM-DD format and then ~~sings~~ prints how old they are in minutes, rounded to the nearest integer, using English words instead of numerals, just like the song from Rent, without any and between words. Since a user might not know the time at which they were born, assume, for simplicity, that the user was born at midnight (i.e., 00:00:00) on that date. And assume that the current time is also midnight. In other words, even if the user runs the program at noon, assume that it’s actually midnight, on the same date. Use datetime.date.today to get today’s date, per docs.python.org/3/library/datetime.html#datetime.date.today.

Structure your program per the below, not only with a main function but also with one or more other functions as well:

from datetime import date

def main():
    ...

...

if __name__ == "__main__":
    main()

You’re welcome to import other (built-in) libraries, or any that are specified in the below hints. Exit via sys.exit if the user does not input a date in YYYY-MM-DD format. Ensure that your program will not raise any exceptions.

Either before or after you implement seasons.py, additionally implement, in a file called test_seasons.py, one or more functions that test your implementation of any functions besides main in seasons.py thoroughly, each of whose names should begin with test_ so that you can execute your tests with:

pytest test_seasons.py

Hints

Note that the date class comes with quite a few methods and “supported operations,” per docs.python.org/3/library/datetime.html#date-objects. In particular, the class implements __sub__, per docs.python.org/3/library/operator.html#operator.__sub__, overloading - in such a way that subtracting one date object from another returns a timedelta object, which itself comes with several (read-only) “instance attributes,” per docs.python.org/3/library/datetime.html#timedelta-objects.
Note that the inflect module comes with quite a few methods, per pypi.org/project/inflect. You can install it with:
```
pip install inflect
```

Demo

Assume that this demo was recorded on January 1, 2000.

Before You Begin

Log into cs50.dev, click on your terminal window, and execute cd by itself. You should find that your terminal window’s prompt resembles the below:

Next execute

mkdir seasons

to make a folder called seasons in your codespace.

Then execute

cd seasons

to change directories into that folder. You should now see your terminal prompt as seasons/ $. You can now execute

code seasons.py

to make a file called seasons.py where you’ll write your program. Be sure to also execute

code test_seasons.py

to create a file called test_seasons.py where you’ll write tests for your program.

How to Test

How to Test `seasons.py`

Here’s how to test seasons.py manually:

Run your program with python seasons.py. Ensure your program prompts you for a birthdate. Type a date one year ago from today, in the specified format, then press Enter. Your program should ~~sing~~ print Five hundred twenty-five thousand, six hundred minutes. If this is a leap year, there should be one more day’s worth of minutes, so expect Five hundred twenty-seven thousand forty minutes instead!
Run your program with python seasons.py. Type a date two years ago from today, in the specified format, then press Enter. Your program should print One million, fifty-one thousand, two hundred minutes (or One million, fifty-two thousand, six hundred forty minutes in a leap year).
Run your program with python seasons.py. Type a date of your choice, but this time use an invalid format. Press Enter and your program should exit using sys.exit without raising an Exception.

How to Test `test_seasons.py`

To test your tests, run pytest test_seasons.py. Try to use correct and incorrect versions of seasons.py to determine how well your tests spot errors:

Ensure you have a correct version of seasons.py. Run your tests by executing pytest test_seasons.py. pytest should show that all of your tests have passed.
Modify one of the functions you’ve implemented in seasons.py and imported into test_seasons.py. One of your functions might, for example, fail to raise a ValueError when it should. Run your tests by executing pytest test_seasons.py. pytest should show that at least one of your tests has failed.
Continue to modify the behavior of seasons.py, creating (predictably) incorrect versions of your implementation. Run your tests by executing pytest test_seasons.py. Do the tests you expect to fail, fail?

You can execute the below to check your code using check50, a program that CS50 will use to test your code when you submit. But be sure to test it yourself as well!

check50 cs50/problems/2022/python/seasons

Green smilies mean your program has passed a test! Red frownies will indicate your program output something unexpected. Visit the URL that check50 outputs to see the input check50 handed to your program, what output it expected, and what output your program actually gave.

How to Submit

In your terminal, execute the below to submit your work.

submit50 cs50/problems/2022/python/seasons