How to Test if a Python Function Throws a Specific Exception?

Barbara Streisand
Release: 2024-11-04 22:13:02
Original
392 people have browsed it

How to Test if a Python Function Throws a Specific Exception?

Testing Python Functions for Exception Throwing

Unit testing in Python often involves verifying the behavior of functions under various conditions, including the raising of expected exceptions. To test if a function throws a specific exception, one can utilize the assertRaises method provided by the unittest module. This method allows developers to assert that an exception will be raised, failing the test if the exception is not thrown.

The syntax for assertRaises is as follows:

<code class="python">assertRaises(exception_class, function, *args, **kwargs)</code>
Copy after login

Where:

  • exception_class: The expected exception class to be thrown.
  • function: The function under test.
  • args and kwargs: Arguments and keyword arguments to be passed to the function.

For example, to test whether a function myfunc raises a SomeCoolException when called, one can write a unit test as follows:

<code class="python">import mymod
import unittest

class MyTestCase(unittest.TestCase):
    def test1(self):
        self.assertRaises(SomeCoolException, mymod.myfunc)</code>
Copy after login

In this test, assertRaises is used to assert that myfunc will raise a SomeCoolException when called without any arguments. If myfunc does not raise the expected exception, the test will fail.

The above is the detailed content of How to Test if a Python Function Throws a Specific Exception?. For more information, please follow other related articles on the PHP Chinese website!

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template