Pytest can be used to test whether a function raises an exception. For instance, consider a division function that raises a ZeroDivisionError if there is an attempt to divide by zero:
def divide(x, y):
return x / y
divide(9, 0)
Attempting to execute this function with zero as the divisor results in a ZeroDivisionError:
Traceback (most recent call last):
File "/users/stanley/code.py", line 5, in <module>
divide(9, 0)
File "/users/stanley/code.py", line 2, in divide
return x / y
~~^~~
ZeroDivisionError: division by zero
To verify that this exception is raised as expected, use the pytest.raises in a test case:
import pytest
def divide(x, y):
return x / y
def test_zero_division():
with pytest.raises(ZeroDivisionError):
divide(9, 0)
When this test is run, it confirms that the divide() function behaves as expected by successfully raising a ZeroDivisionError when dividing by zero, indicated by a passing test result:
...
collected 1 item
test.py::test_zero_division PASSED [100%]
============================== 1 passed in 0.00s ===============================
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
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