Test Driven Development in Python

1. Test Driven Development in Python
Anoop Thomas Mathew
Agiliq Info Solutions Pvt. Ltd.

2. Overview
●About TDD
●TDD and Python
●unittests
●Developing with Tests
●Concluding Remarks
●Open Discussion

3. “
Walking on water and developing software
from a specification are easy if both are
frozen. - Edward V Berard
”

4. About Test Driven Development
(TDD)
●Write tests for the use case
●Run it (make sure it fails and fails
miserably)
●Write code and implement the required
functionality with relevant level of detail
●Run the test
●Write test for addition features
●Run all test
●Watch it succeed. Have a cup of coffee !

5. Advantages of TDD
●application is determined by using it
●written minimal amount of application code
–total application + tests is probably more
–objects: simpler, stand-alone, minimal
dependencies
● tends to result in extensible architectures
● instant feedback

6. Unittest
import unittest
class MyTest(unittest.TestCase):
def testMethod(self):
self.assertEqual(1 + 2, 3, "1 + 2 !=3")
if __name__ == '__main__':
unittest.main()

7. The Test
import unittest
from demo import Greater
class DemoTest(unittest.TestCase):
def test_number(self):
comparator = Greater()
result = comparator.greater(10,5)
self.assertTrue(result)
def test_char(self):
comparator = Greater()
result = comparator.greater('abcxyz', 'AB')
self.assertTrue(result)
def test_char_equal(self):
comparator = Greater()
result = comparator.greater('4', 3)
self.assertTrue(result)
if __name__ == '__main__':
unittest.main()

8. The Program
class Greater(object):
def greater(self, val1, val2):
if type(val1) ==str or type(val2) == str:
val1 = str(val1)
val2 = str(val2)
sum1 = sum([ord(i) for i in val1])
sum2 = sum([ord(i) for i in val2])
if sum1 > sum2:
return True
else:
return False
if val1>val2:
return True
else:
return False

9. Test Again
1. Add new test for features/bugs
2. Resolve the issue, make the test succeed.
3. Iterate from Step 1

10. Beware!!!
Murphy is everywhere.

11. Let's Discuss