The document discusses unit testing in Python. It defines unit testing as testing individual units or components of code to determine if they work as intended. It covers key concepts like test cases, test fixtures, test suites, and test runners. It also provides examples of how to write unit tests in Python using the unittest module and concepts like assertions, setup and teardown methods.

What's hot

Viewers also liked

Similar to Python Programming Essentials - M39 - Unit Testing

More from P3 InfoTech Solutions Pvt. Ltd.

Python Programming Essentials - M39 - Unit Testing

• 1.
  http://www.skillbrew.com/SkillbrewTalent brewed bytheindustry itselfUnit TestingPavan Verma@YinYangPavanFounder, P3 InfoTech Solutions Pvt. Ltd.Python Programming Essentials
• 2.
  © SkillBrew http://skillbrew.comWhatis Unit Testing A software testing method by which individualunits of source code are tested to determine ifthey are fit for use. Unit testing is a software developmentprocess in which the smallest testable parts ofan application, called units, are individuallyand independently scrutinized for properoperation. Unit testing is often automated butit can also be done manually.
• 3.
  © SkillBrew http://skillbrew.comUnitTesting Glossary test fixture – A test fixture represents thepreparation needed to perform one or moretests, and any associate cleanup actions. Thismay involve, for example, creating temporary orproxy databases, directories, or starting a serverprocess.
• 4.
  © SkillBrew http://skillbrew.comUnitTesting Glossary (2) test case – A test case is the smallest unitof testing. It checks for a specific responseto a particular set of inputs. Python unittest module provides a baseclass, TestCase, which may be used tocreate new test cases.
• 5.
  © SkillBrew http://skillbrew.comUnitTesting Glossary (3) test suite – A test suite is a collection oftest cases, test suites, or both. It is used toaggregate tests that should be executedtogether.
• 6.
  © SkillBrew http://skillbrew.comUnitTesting Glossary (4) test runner – A test runner is a componentwhich orchestrates the execution of testsand provides the outcome to the user. The runner may use a graphical interface,a textual interface, or return a special valueto indicate the results of executing thetests.
• 7.
  © SkillBrew http://skillbrew.comUnittestmodule The unittest module started life as thethird-party module PyUnit. PyUnit was a Python port of JUnit, theJava unit testing framework.
• 8.
  © SkillBrew http://skillbrew.comProgramto test – primes.pydef is_prime(number):"""Return True if *number* is prime.""“for element in range(number):if number % element == 0:return Falsereturn True
• 9.
  © SkillBrew http://skillbrew.comBasicunit test exampleimport unittestfrom primes import is_primeclass PrimesTestCase(unittest.TestCase):"""Tests for `primes.py`.""“def test_is_five_prime(self):"""Is five successfully determined to beprime?""“self.assertTrue(is_prime(5))if __name__ == '__main__':unittest.main()
• 10.
  © SkillBrew http://skillbrew.comRunninga unit test$ python test_primes.pyE ======================================================================ERROR: test_is_five_prime (__main__.PrimesTestCase)----------------------------------------------------------------------Traceback (most recent call last):File "test_primes.py", line 8, in test_is_five_primeself.assertTrue(is_prime(5))File "/home/jknupp/code/github_code/blug_private/primes.py", line 4, inis_primeif number % element == 0: ZeroDivisionError: integer division or modulo by zero----------------------------------------------------------------------Ran 1 test in 0.000s
• 11.
  © SkillBrew http://skillbrew.comAssertionsMethodChecks thatassertEqual(a, b) a == bassertNotEqual(a, b) a != bassertTrue(x) bool(x) is TrueassertFalse(x) bool(x) is FalseassertIs(a, b) a is bassertIsNot(a, b) a is not bassertIsNone(x) x is NoneassertIsNotNone(x) x is not NoneassertIn(a, b) a in bassertNotIn(a, b) a not in bassertIsInstance(a, b) isinstance(a, b)assertNotIsInstance(a, b) not isinstance(a, b)
• 12.
  © SkillBrew http://skillbrew.comAssertions(2)Method Checks thatassertAlmostEqual(a, b) round(a-b, 7) == 0assertNotAlmostEqual(a, b) round(a-b, 7) != 0assertGreater(a, b) a > bassertGreaterEqual(a, b) a >= bassertLess(a, b) a < bassertLessEqual(a, b) a <= bassertRegexpMatches(s, r) r.search(s)assertNotRegexpMatches(s, r) not r.search(s)assertItemsEqual(a, b)sorted(a) == sorted(b) and works withunhashable objsassertDictContainsSubset(a, b) all the key/value pairs in a exist in b
• 13.
  © SkillBrew http://skillbrew.comsetUpand tearDown#!/usr/bin/pythonimport unittestclass FooTest(unittest.TestCase):"""Sample test case"""# preparing to testdef setUp(self):""" Setting up for the test """print "FooTest:setUp_:begin"## do something...print "FooTest:setUp_:end"# ending the test
• 14.
  © SkillBrew http://skillbrew.comsetUpand tearDown (2)def tearDown(self):"""Cleaning up after the test"""print "FooTest:tearDown_:begin" ## dosomething...print "FooTest:tearDown_:end" # test routine Adef testA(self):"""Test routine A"""print "FooTest:testA"# test routine Bdef testB(self):"""Test routine B"""print "FooTest:testB"
• 15.
  © SkillBrew http://skillbrew.comsetUpand tearDown (3)
• 16.
  © SkillBrew http://skillbrew.comUnittestfeatures setupClass() / tearDownClass() Skip tests Expected failures
• 17.
  © SkillBrew http://skillbrew.comTestingFrameworks pytest Nose
• 18.
  © SkillBrew http://skillbrew.comCodecoverage coveragehttp://nedbatchelder.com/code/coverage/
• 19.
  © SkillBrew http://skillbrew.comReferenceshttps://docs.python.org/2/library/unittest.html http://pytest.org/ http://nose.readthedocs.org/ http://nedbatchelder.com/code/coverage/