Re-requesting a Vanity Plate
In a file called
plates.py, reimplement Vanity Plates from Problem Set 2, restructuring your code per the below, wherein
is_valid still expects a
str as input and returns
True if that
str meets all requirements and
False if it does not, but
main is only called if the value of
def main(): ... def is_valid(s): ... if __name__ == "__main__": main()
Then, in a file called
test_plates.py, implement four or more functions that collectively test your implementation of
is_valid thoroughly, each of whose names should begin with
test_ so that you can execute your tests with:
- Be sure to include
from plates import is_valid
test_plates.pyso that you can call
is_validin your tests.
- Take care to
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:
to make a folder called
test_plates in your codespace.
to change directories into that folder. You should now see your terminal prompt as
test_plates/ $. You can now execute
to make a file called
test_plates.py where you’ll write your tests.
How to Test
To test your tests, run
pytest test_plates.py. Be sure you have a copy of a
plates.py file in the same folder. Try to use correct and incorrect versions of
plates.py to determine how well your tests spot errors:
- Ensure you have a correct version of
plates.py. Run your tests by executing
pytestshould show that all of your tests have passed.
- Modify the correct version of
plates.py, perhaps eliminating some of its constraints. Your program might, for example, mistakenly print “Valid” for a license plate of any length! Run your tests by executing
pytestshould show that at least one of your tests has failed.
You can execute the below to check your tests using
check50, a program CS50 will use to test your code when you submit. (Now there are tests to test your tests!). Be sure to test your tests yourself and determine which tests are needed to ensure
plates.py is checked thoroughly.
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.