Python Probability Testing Type Issue

Python
1

I’m having an error in my python probability calculator with the testing suite. I think my program is working properly, but I get the following error from the tests:

..E
======================================================================
ERROR: test_prob_experiment (test_module.UnitTests)
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Traceback (most recent call last):
  File "/home/runner/fcc-probability-calculator-1/test_module.py", line 31, in test_prob_experiment
    self.assertAlmostEqual(actual, expected, delta = 0.01, msg = 'Expected experiment method to return a different probability.')
  File "/usr/lib/python3.8/unittest/case.py", line 943, in assertAlmostEqual
    diff = abs(first - second)
TypeError: unsupported operand type(s) for -: 'str' and 'float'

----------------------------------------------------------------------
Ran 3 tests in 0.186s

FAILED (errors=1)
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Here’s my repl.it for referencing what’s going on, I cannot explain it any further really, I tested the types of my outputs, the probability calculator is returning a float, which should be all the test is evaluating?

My current solution

2

Notice the issue is with case when number of balls to draw is higher than the number of balls in hat. Take a closer look at the specification, in such case, after drawing all balls from the hat, they are supposed to be returned to the hat for further drawing.

3

Ohhhh you are right! It was that edge case that I added for no reason lol :). All good, it works now! Question: did you notice that right away when you were looking at my solution, or you were able to somehow tell from the error message? Thank you!

4

Well it was both. Error was saying about str - TypeError: unsupported operand type(s) for -: 'str' and 'float', so it then required looking in code where function might have been returning str and why.

1 Like
5

Thank you! I will save myself a lot of time as I get better as assessing errors!