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Slides from PyOhio, a brief tour of unittest and doctest.
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magePython Testing Fundamentals
Saturday, July 28, 2012
PyOhio
Ohio State University
Columbus, OH
Chris Calloway
University of North Carolina
Department of Marine Sciences
Python Testing Fundamentals
PyCamp™ Programming For The People
Copyright © 2012
Trizpug
mage
http://drunkenpython.org/pytestfund.pdf
http://drunkenpython.org/pyohio.zip
http://drunkenpython.org/pyohio.tgz
Python Testing Fundamentals
PyCamp™ Programming For The People
Copyright © 2012
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•Fundamental
•Python 3.2.3
•Assertion
•Unittest
•Doctest
Programming For The People
About This Tutorial
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“Untested Code is Broken Code”
- Phillip von Weitershausen
Programming For The People
Why Test?
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Programming For The People
Why Test?
•Tests help you design good code
•Test help you find bugs
•Tests help you document code
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Programming For The People
Assert Statements
•Assert statements use the assert keyword
•Assert statements raise AssertionError
•Based on bool test expressions
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Programming For The People
Assert Statements
>>> assert 1 == 1
keyword
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Programming For The People
Assert Statements
>>> assert 1 == 1
expression
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Programming For The People
Assert Statements
>>> assert expression
is almost the same as:
>>> if not expression:
... raise AssertionError()
>>>
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Programming For The People
Assert Statements
>>> assert 1 == 1
>>> assert 1 == 2
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
>>>
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Assert Statements
•A second optional expression on the assert statement provides a message for the AssertionError
•This helps you distinguish one assertion from another
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Programming For The People
Assert Statements
>>> assert 1 == 2, "Reality check"
second expression
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Programming For The People
Assert Statements
assert expression1, expression2
is almost the same as:
if not expression1:
raise AssertionError(expression2)
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Programming For The People
Assert Statements
>>> assert 1 == 2, "Reality check"
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError: Reality check
>>>
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Programming For The People
Assert Statements
•Assertions may be sprinkled liberally throughout your code to check that your code is running as expected
•Think of assertions as Python's reality check
•You decide what "reality" is
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Assert Statements
profit = bottom_line(today)
assert profit > 0, "Unacceptable!"
projection = growth(tomorrow)
assert projection > profit, "UR fired!"
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bigbiz.py:
Programming For The People
Assert Statements
•Assertions usually generate unhandled exceptions which halt your program
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Assert Statements
bigbiz.py:
Text
def bottom_line(timestamp):
"""Compute the profit on date."""
return -1e6
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Programming For The People
Assert Statements
> python bigbiz.py
Traceback (most recent call last):
File "bigbiz.py", line 20, in <module>
assert profit > 0, "Unacceptable!"
AssertionError: Unacceptable!
>
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Programming For The People
Assert Statements
•By using Python's -i command line switch, you may interactively inspect what went wrong where the assertion was raised
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Programming For The People
Assert Statements
> python -i bigbiz.py Traceback (most recent call last): File "bigbiz.py", line 20, in <module> assert profit > 0, "Unacceptable!"AssertionError: Unacceptable!>>> profit-1000000.0>>>
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Assert Statements
•By using Python's -i command line switch, you may use also Python's debugger to see what went wrong at the point of assertion
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Programming For The People
Assert Statements
> python -i bigbiz.pyTraceback (most recent call last): File "bigbiz.py", line 20, in <module> assert profit > 0, "Unacceptable!"AssertionError: Unacceptable!>>> import pdb>>> pdb.pm()> /Users/cbc/pyohio/bigbiz.py(20)<module>()-> assert profit > 0, "Unacceptable!"(Pdb) profit-1000000.0(Pdb)
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Programming For The People
Assert Statements
•Assertions may be turned off by "optimizing" Python with the -O command line switch
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Programming For The People
Assert Statements
> python -O
>>> assert 1 == 2
>>>
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Assert Statements
> python -O bigbiz.py
Profit is -1000000.00 USD.
Projected profit is -2000000.00 USD.
>
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Programming For The People
Assert Statements
•It's a fine line whether assert statements are testing or debugging
•Assert statements are slightly more sophisticated than using print
•But assert statements form the basis for testing in Python
•In Python, a test is an assertion of an expected result
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Programming For The People
Unittest Module
•Unittest is "batteries included" in Python
•Unittest helps you separate test code from the code under test
•Unittest helps you write tests before code
•Unittest helps you organize and discover all your tests
•Unittest hooks into many other Python tools
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Programming For The People
Unittest Module
>>> import unittest
>>> dir(unittest)
['BaseTestSuite', 'FunctionTestCase', 'SkipTest', 'TestCase', 'TestLoader', 'TestProgram', 'TestResult', 'TestSuite', 'TextTestResult', 'TextTestRunner', '_TextTestResult', '__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__name__', '__package__', '__path__', '__unittest', 'case', 'defaultTestLoader', 'expectedFailure', 'findTestCases', 'getTestCaseNames', 'installHandler', 'loader', 'main', 'makeSuite', 'registerResult', 'removeHandler', 'removeResult', 'result', 'runner', 'signals', 'skip', 'skipIf', 'skipUnless', 'suite', 'util']
>>>
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TestCase Class
•unittest.TestCase is a class
•You create TestCase subclasses
•You add methods whose names start with "test" to your TestCase subclass
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TestCase Class
•Each test method you supply in your subclass executes a TestCase supplied method whose name starts with "assert"
•A TestCase provides what is known as a "test fixture" in testing parlance
•The unittest module provides many ways to run the test methods of your text fixture
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Programming For The People
TestCase Class
test_operator.py:
Text
"""Demonstrate the unittest module."""
import operator
import unittest
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Programming For The People
TestCase Class
test_operator.py:
Textclass TestOperator(unittest.TestCase):
"""Test the operator module."""
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Programming For The People
TestCase Class
test_operator.py:
Text
def test_add(self):
"""Test the add function."""
self.assertEqual(operator.add(2, 2),
2 + 2)
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TestCase Class
test_operator.py:
Text
def test_sub(self):
"""Test the sub function."""
self.assertEqual(operator.sub(4, 2),
4 - 2)
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TestCase Class
test_operator.py:
Text
def test_mul(self):
"""Test the mul function."""
self.assertEqual(operator.mul(2, 2),
2 * 2)
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TestCase Class
test_operator.py:
Textif __name__ == "__main__":
unittest.main()
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main Class
•unittest.main is also a class
•unittest.main is normally only used within a script containing test fixtures
•When unittest.main is instantiated, all of the tests in the script's namespace are loaded and run
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main Class
> python test_operator.py
...
--------------------------------------Ran 3 tests in 0.001s
OK
>
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Programming For The People
TestLoader Class
•Notice that nowhere does it appear that your script has instantiated your TestCase subclass or execute any of its methods
•unittest.main instead instantiates a special unittest.TestLoader class which has methods to search your module for TestCase classes and instantiate them
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TestRunner Class
•Once the TestLoader instance created by unittest.main discovers and instantiates the TestCase in your script, unittest.main instantiates a special unittest.TestRunner class which has methods to run the methods of your TestCase instances
•unittest.main takes care of handling TestLoaders and TestRunners for you!
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TestRunner Class
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TestCase(superclass)
TestOperator(subclass)
unittest.main(instance)
TestLoader(instance)
TestRunner(instance)
TestOperator(instance)
createTests()
runTests()
discover()
run()
Programming For The People
main Class
test_operator.py:
Textif __name__ == "__main__":
unittest.main(verbosity=2)
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main Class
> python test_operator.py test_add (__main__.TestOperator)Test the add function. ... oktest_mul (__main__.TestOperator)Test the mul function. ... oktest_sub (__main__.TestOperator)Test the sub function. ... ok
--------------------------------------Ran 3 tests in 0.001s
OK>
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main Class
•Notice that your tests did not run in the same order in which they were defined
•unittest.main loads the test methods from your TestCase instance's __dict__ attribute
•Dictionaries are unordered
•unittest.main() runs the test methods in your Python's built-in order for strings
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TestCase Class
test_operator.py:
Text
def test_add(self):
"""Test the add function."""
self.assertEqual(operator.add(2, 2),
2 + 3)
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TestCase Class
> python test_operator.py F..======================================FAIL: test_add (__main__.TestOperator)Test the add function.--------------------------------------Traceback (most recent call last): File "test_operator.py", line 13, in test_add self.assertEqual(operator.add(2, 2), 2 + 3)AssertionError: 4 != 5
--------------------------------------Ran 3 tests in 0.082s
FAILED (failures=1)>
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TestCase Class
test_operator.py:
Text
def test_add(self):
"""Test the add function."""
self.assertEqual(operator.add(2, 2),
2 + "2")
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TestCase Class
> python test_operator.py E..================================================ERROR: test_add (__main__.TestOperator)Test the add function.------------------------------------------------Traceback (most recent call last): File "test_operator.py", line 13, in test_add self.assertEqual(operator.add(2, 2), 2 + "2")TypeError: unsupported operand type(s) for +:int' and 'str'
------------------------------------------------Ran 3 tests in 0.001s
FAILED (errors=1)>
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TestResult Class
•Running a test results in one of three outcomes:
★ Success (expected result)
★ Failure (unexpected result)
★ Error (error running the test)
•The outcomes of all tests are accumulated in a unittest.TestResult instance
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TestResult Class
•Most of the time you will not need to create your own TestResult instances
•Most of the ways you will run tests will instantiate and report a TestResult for you
•But to run a test always requires a TestResult instance somewhere
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TestResult Class
> python -m unittest test_operator
...
--------------------------------------
Ran 3 tests in 0.000s
OK
>
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TestResult Class
> python -m unittest \
test_operator.TestOperator
...
--------------------------------------
Ran 3 tests in 0.000s
OK
>
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TestResult Class
> python -m unittest \
test_operator.TestOperator.test_add
.
--------------------------------------
Ran 1 test in 0.000s
OK
>
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TestResult Class
> python -m unittest test_operator.py
...
--------------------------------------
Ran 3 tests in 0.000s
OK
>
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TestResult Class
> python -m unittest -v test_operator test_add (test_operator.TestOperator)Test the add function. ... oktest_mul (test_operator.TestOperator)Test the mul function. ... oktest_sub (test_operator.TestOperator)Test the sub function. ... ok
--------------------------------------Ran 3 tests in 0.001s
OK>
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TestResult Class
> python -m unittest -hUsage: python -m unittest [options] [tests]
Options: -h, --help Show this message -v, --verbose Verbose output -q, --quiet Minimal output -f, --failfast Stop on first failure -c, --catch Catch control-C and display results -b, --buffer Buffer stdout and stderr during test runs[tests] can be a list of any number of testmodules, classes and test methods.
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load_tests Protocol
> python -m unittest
.......
--------------------------------------
Ran 7 tests in 0.000s
OK
>
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load_tests Protocol
Alternative Usage: python -m unittest \ discover [options]
Options: -s directory Directory to start discovery ('.' default) -p pattern Pattern to match test files ('test*.py' default) -t directory Top level directory of project (default to start directory)For test discovery all test modules must beimportable from the top level directory.
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TestCase Class
•Notice that TestCase.assertEqual does not appear to raise an unhandled AssertionError
•The TestRunner instance handles the AssertionError for failing tests and updates the TestResult instance
•TestCase.assertEqual is but one of many test methods you may use in your tests
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TestCase Class
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Method Tests If
assertEqual(a, b) a == b
assertNotEqual(a, b) a != b
assertTrue(x) bool(x) is True
assertFalse(x) bool(x) is False
assertIs(a, b) a is b
assertIsNot(a, b) a is not b
assertIsNone(x) x is None
assertIsNotNone(x) x is not None
assertIn(a, b) a in b
assertNotIn(a, b) a not in b
assertIsInstance(a, b) isinstance(a, b)
assertNotIsInstance(a, b) not isinstance(a, b)
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TestCase Class
•You not only need to test if your code produces expected results, you also need to test if your code handles unexpected results in an expected manner!
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TestCase Class
test_operatorNG.py:
Text
def test_add_str(self):
"""Test bad args for add."""
with self.assertRaises(TypeError):
operator.add(2, "2")
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TestCase Class
> python -m unittest test_operatorNG
....
--------------------------------------
Ran 4 tests in 0.000s
OK
>
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TestCase Class
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Method Tests If
assertRaises(exception) exception raised
assertRaisesRegex(exception, regex) exception raised and message matches regex
assertWarns(warning) warning raised
assertWarnsRegex(warning, regex) warning raised and message matches regex
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TestCase Class
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Method Tests If
assertAlmostEqual(a, b) round(a-b, 7) == 0
assertNotAlmostEqual(a, b) round(a-b, 7) != 0
assertGreater(a, b) a > b
assertGreaterEqual(a, b) a >= b
assertLess(a, b) a < b
assertLessEqual(a, b) a <= b
assertRegex(s, re) s matches regex
assertNotRegex(s, re) s does not match regex
assertCountEqual(a, b)a and b have the same elements in the same number, regardless of order
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TestCase Class
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Method Compares
assertMultiLineEqual(a, b) Strings
assertSequenceEqual(a, b) Sequences
assertListEqual(a, b) Lists
assertTupleEqual(a, b) Tuples
assertSetEqual(a, b) Sets and Frozensets
assertDictEqual(a, b) Dictionaries
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TestCase Class
>>> [attr for attr
... in dir(unittest.TestCase)
... if attr.startswith('assert')]
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•Plus many more!
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TestCase Class
>>> help(unittest.TestCase.
... assertDictContainsSubset)
Help on function assertDictContainsSubset in module unittest.case:
assertDictContainsSubset(self, subset,
dictionary, msg=None)
Checks whether dictionary is a superset of subset.
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TestSuite Class
test_operatorNG2.py:
Text
"""Demonstrate the unittest module."""
import operator
import unittest
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TestSuite Class
test_operatorNG2.py:
Textclass TestAdd(unittest.TestCase):
"""Test the add function."""
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TestSuite Class
test_operatorNG2.py:
Text
def test_add_int(self):
"""Test with ints."""
self.assertEqual(operator.add(2, 2),
2 + 2)
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TestSuite Class
test_operatorNG2.py:
Text
def test_add_str(self):
"""Test with strs."""
with self.assertRaises(TypeError):
operator.add(2, "2")
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TestSuite Class
test_operatorNG2.py:
Textclass TestSub(unittest.TestCase):
"""Test the sub function."""
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TestSuite Class
test_operatorNG2.py:
Text
def test_sub_int(self):
"""Test with ints."""
self.assertEqual(operator.sub(4, 2),
4 - 2)
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TestSuite Class
test_operatorNG2.py:
Text
def test_sub_str(self):
"""Test with strs."""
with self.assertRaises(TypeError):
operator.sub(4, "2")
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TestSuite Class
test_operatorNG2.py:
Textclass TestMul(unittest.TestCase):
"""Test the mul function."""
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TestSuite Class
test_operatorNG2.py:
Text
def test_mul_int(self):
"""Test with ints."""
self.assertEqual(operator.mul(2, 2),
2 * 2)
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TestSuite Class
test_operatorNG2.py:
Text
def test_mul_str(self):
"""Test with strs."""
self.assertEqual(operator.mul(2, "2"),
"22")
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TestSuite Class
test_operatorNG2.py:
Text
str_suite = unittest.TestSuite()
str_suite.addTest(TestAdd("test_add_str"))
str_suite.addTest(TestSub("test_sub_str"))
str_suite.addTest(TestMul("test_mul_str"))
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TestSuite Class
test_operatorNG2.py:
Textif __name__ == "__main__":
unittest.main()
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TestSuite Class
•Objects you have bound in the test_operatorNG2 namespace:
•TestAdd class
•TestSub class
•TestMul class
•str_suite instance
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TestSuite Class
> python test_operatorNG2.py
......
--------------------------------------
Ran 6 tests in 0.001s
OK
>
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TestSuite Class
> python -m unittest \
test_operatorNG2.str_suite
...
--------------------------------------
Ran 3 tests in 0.000s
OK
>
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TestSuite Class
> python -m unittest -v \ test_operatorNG2.str_suitetest_add_str (test_operatorNG2.TestAdd)Test with strs. ... oktest_sub_str (test_operatorNG2.TestSub)Test with strs. ... oktest_mul_str (test_operatorNG2.TestMul)Test with strs. ... ok
--------------------------------------Ran 3 tests in 0.001sOK>
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Programming For The People
Organizing Tests
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pyohio-+ bin/python pycamp-+ __init__.py setup.py fibonacci.py triangle.py tests-+ __init__.py test_fibonacci.py test_triangular.py
Programming For The People
Organizing Tests
> python pycamp/fibonacci.py 100
1 2 3 5 8 13 21 34 55 89
> python
>>> from pycamp.fibonacci import fib
>>> fib(100)
[1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
>>>
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Organizing Tests
> python pycamp/triangular.py 100
1 3 6 10 15 21 28 36 45 55 66 78 91
> python
>>> from pycamp.triangular import tri
>>> tri(100)
[1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91]
>>>
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Text
"""Tests for the fibonacci module."""
from pycamp import fibonacci
import unittest
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Textclass TestFibonacci(unittest.TestCase):
"""Test fibonacci's functions."""
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TestCase Class
•TestCase also supplies methods you override
•TestCase.setUp() is called before every test method you supply in your subclass
•TestCase.tearDown() is called after every test method you supply in your subclass
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TestCase Class
•Your TestCase subclasses, along with all the test methods you supply, and all the TestCase supplied methods you override, possibly all bundled up into a TestSuite, are collectively known as a "test fixture" in testing parlance
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Text
def setUp(self):
"""Test fixture build."""
self.lessThan100 = [1, 2, 3, 5, 8,
13, 21, 34, 55,
89, ]
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Text
def test_fib_100(self):
"""Test fib for numbers < 100."""
self.assertEqual(fibonacci.fib(100),
self.lessThan100)
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Text
def test_fib_10(self):
"""Test fib for numbers < 10."""
self.assertEqual(fibonacci.fib(10),
self.lessThan100[:5])
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Organizing Tests
pycamp/tests/test_fibonacci.py:
Textif __name__ == "__main__":
unittest.main()
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Organizing Tests
pycamp/tests/test_triangular.py:
Text
"""Tests for the triangular module."""
from pycamp import triangular
import unittest
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Organizing Tests
pycamp/tests/test_triangular.py:
Textclass TestTriangular(unittest.TestCase):
"""Test triangular's functions."""
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Organizing Tests
pycamp/tests/test_triangular.py:
Text
def setUp(self):
"""Test fixture build."""
self.lessThan100 = [1, 3, 6, 10, 15,
21, 28, 36, 45,
55, 66, 78, 91, ]
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Organizing Tests
pycamp/tests/test_triangular.py:
Text
def test_tri_100(self):
"""Test tri for numbers < 100."""
self.assertEqual(triangular.tri(100),
self.lessThan100)
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Organizing Tests
pycamp/tests/test_triangular.py:
Text
def test_tri_10(self):
"""Test tri for numbers < 10."""
self.assertEqual(triangular.tri(10),
self.lessThan100[:3])
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Organizing Tests
pycamp/tests/test_triangular.py:
Textif __name__ == "__main__":
unittest.main()
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Organizing Tests
> python -m unittest discover \
-s pycamp -t .
....
--------------------------------------Ran 4 tests in 0.001s
OK
>
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Organizing Tests
pycamp/setup.py:
Text
"""Setup for pycamp package."""
from setuptools import setup, \
find_packages
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Organizing Tests
pycamp/setup.py:
Text
setup(
name="pycamp",
version="1.0",
packages=find_packages(),
author="Chris Calloway",
author_email="[email protected]",
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Organizing Tests
pycamp/setup.py:
Text
description="Testing Fundamentals",
license="PSF",
keywords="testing pycamp",
url="http://pycamp.org",
test_suite="pycamp.tests",
)
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Organizing Tests
> python pycamp/setup.py test
running test
..lots of output omitted for brevity..
--------------------------------------
Ran 4 tests in 0.001s
OK
>
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Organizing Tests
> python pycamp/setup.py test
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Organizing Tests
> python pycamp/setup.py install
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Organizing Tests
> python pycamp/setup.py register
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Unittest Module
•unittest provides nice separation of tests from code
•One person can write tests, while another writes code to make tests pass
•unittest provides fine grain control over what tests to run when
•unittest conforms to industry standard testing
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Unittest Module
•However, it can be difficult to keep tests and code in sync
•Also, writing code to test code can also be more difficult than the code under test
•What about testing and debugging the test code?
•Reading unittest tests is a poor way to figure out how code works
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Doctest Module
•Informally, even without written tests, you probably already test your code by simply using it as it was meant to be used
•You've probably imported your code at a Python prompt and inspect how it works manually
•You just don't yet have a way of repeating that informal testing in an automated manner
•What you need is the doctest module
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Doctest Module
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pyohio-+ bin/python pycampNG-+ __init__.py setup.py fibonacci.py triangle.py tests-+ __init__.py test_pycamp.py
Programming For The People
Doctest Module
pycampNG/fibonacci.py:
Text
"""A module of functions about non-zero Fibonacci numbers.
>>> import fibonacci
>>>
"""
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Doctest Module
pycampNG/fibonacci.py:
Text
def fib(n):
"""Return the sequence of non-zero
Fibonacci numbers less than n.
fib(n) -> [0 < fibonacci numbers < n]
where n in an int.
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Doctest Module
pycampNG/fibonacci.py:
Text
>>> lessThan100 = [1, 2, 3, 5, 8, 13,
... 21, 34, 55, 89]
>>> fib(100) == lessThan100
True
>>> fib(10) == lessThan100[:5]
True
"""
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Doctest Module
pycampNG/triangular.py:
Text
"""A module of functions about non-zero triangular numbers.
>>> import triangular
>>>
"""
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Doctest Module
pycampNG/triangular.py:
Text
def tri(n):
"""Return the sequence of non-zero
triangular numbers less than n.
tri(n) -> [0 < triangular numbers < n]
where n in an int.
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Doctest Module
pycampNG/triangular.py:
Text
>>> lessThan100 = [1, 3, 6, 10, 15,
21, 28, 36, 45,
55, 66, 78, 91]
>>> tri(100) == lessThan100
True
>>> tri(10) == lessThan100[:3]
True
"""
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Doctest Module
> python -m doctest pycampNG/fibonacci.py
>
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Doctest Module
> python -m doctest -v \
pycampNG/fibonacci.py
Trying:
import fibonacci
Expecting nothing
ok
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Doctest Module
Trying:
lessThan100 = [1, 2, 3, 5, 8, 13,
21, 34, 55, 89]
Expecting nothing
ok
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Doctest Module
Trying:
fib(100) == lessThan100
Expecting:
True
ok
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Doctest Module
Trying:
fib(10) == lessThan100[:5]
Expecting:
True
ok
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Doctest Module
2 items passed all tests:
1 tests in fibonacci
3 tests in fibonacci.fib
4 tests in 2 items.
4 passed and 0 failed.
Test passed.
>
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Doctest Module
> python -m doctest pycampNG/triangular.py
>
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Doctest Module
pycampNG/fibonacci.py:
Text
if __name__ == '__main__':
if sys.argv[1].lower() == 'test':
import doctest
doctest.testmod()
else:
print(" ".join([str(x) for x in
fib(int(sys.argv[1]))]))
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Doctest Module
pycampNG/triangular.py:
Text
if __name__ == '__main__':
if sys.argv[1].lower() == 'test':
import doctest
doctest.testmod()
else:
print(" ".join([str(x) for x in
tri(int(sys.argv[1]))]))
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Doctest Module
> python pycampNG/fibonacci.py test
> python pycampNG/fibonacci.py 100
1 2 3 5 8 13 21 34 55 89
>
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Doctest Module
> python pycampNG/triangular.py test
> python pycampNG/triangular.py 100
1 3 6 10 15 21 28 36 45 55 66 78 91
>
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Doctest Module
•But what about setuptools.setup?
•The test_suite argument of setup triggers unittest discovery, not doctest discovery
•What you need is a way to turn doctests into unittests
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Doctest Module
•The doctest.DocTestSuite() function searches a module for doctests and converts them into a unittest.TestSuite instance
•Now all you need is a way to communicate your TestSuite instance(s) to unittest discovery
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load_tests Protocol
def load_tests(loader,
tests,
pattern):
...
return tests
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load_tests Protocol
def load_tests(loader,
tests,
pattern):
...
return tests
unittest.TestLoader
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load_tests Protocol
def load_tests(loader,
tests,
pattern):
...
return tests
unittest.TestSuite
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load_tests Protocol
def load_tests(loader,
tests,
pattern):
...
return tests
"test*.py"
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load_tests Protocol
def load_tests(loader,
tests,
pattern):
...
return tests
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load_tests Protocol
pycampNG/tests/test_pycamp.py:
Textimport doctest
from pycampNG import fibonacci
from pycampNG import triangular
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load_tests Protocol
pycampNG/tests/test_pycamp.py:
Text
def load_tests(loader, tests, pattern):
tests.addTests(
doctest.DocTestSuite(fibonacci))
tests.addTests(
doctest.DocTestSuite(triangular))
return tests
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Programming For The People
load_tests Protocol
pycampNG/tests/test_pycamp.py:
Text
def load_tests(loader, tests, pattern):
tests.addTests(
doctest.DocTestSuite(fibonacci))
tests.addTests(
doctest.DocTestSuite(triangular))
return tests
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load_tests Protocol
pycampNG/tests/test_pycamp.py:
Text
def load_tests(loader, tests, pattern):
tests.addTests(
doctest.DocTestSuite(fibonacci))
tests.addTests(
doctest.DocTestSuite(triangular))
return tests
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load_tests Protocol
pycampNG/tests/test_pycamp.py:
Text
def load_tests(loader, tests, pattern):
tests.addTests(
doctest.DocTestSuite(fibonacci))
tests.addTests(
doctest.DocTestSuite(triangular))
return tests
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Programming For The People
load_tests Protocol
pycamp/setup.py:
Text
setup(
name="pycampNG",
...
test_suite="pycampNG.tests",
)
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Programming For The People
load_tests Protocol
> python pycampNG/setup.py test
running test
..lots of output omitted for brevity..
--------------------------------------
Ran 4 tests in 0.001s
OK
>
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Doctest Module
Together, the doctest.DocTestSuite() function and the load_tests protocol from the unittest module enable you to use all the tools available for unittests with doctests
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Python Testing Tools Taxonomy
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Test Driven Development
•Doctests enable you to do Test Driven Development (TDD)
•TDD is where you write tests for your code before you write code
•Then you write code to make your tests pass
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Test Driven Development
•When all your tests pass, then you have finished coding
•You can develop your code incrementally, writing one test at a time, then getting that one test to pass
•That means you can stop coding at any time
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Test Driven Development
•If your code needs more features, then what you really need is more tests, and code which makes those tests pass
•Writing tests lets you see what the API for your code is up front, instead of having it designed haphazardly
•Writing tests can provide the documentation for your code
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Test Driven Development
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Tomorrow 12:15pm in Barbie Tootle
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Programming For The People
Thank You
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