Writing tests for functions and classes in Python

Here's a simple example code that I wrote to test a mathOps class in Python. I use the unittest package which is part of the Python Standard Library.

As you can see, the mathOps class has two attributes, a,b, and there are methods defined that take care of addition, subtraction, multiplication and division. Now, I want to write a code, that tests mathOps class objects to make sure that the methods are giving the output we desire.

One interesting thing to note is the last function/test defined in the mathOpsTest class. The decorator @unittest.expectedFailure tells the testing framework that this test is expected to fail, given that we're passing vectors/arrays to the add method, expecting it to perform vector addition, where as the add method expects input of type Float. The traits package does this type-checking to make sure that the inputs we give are of the right kind!


 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
import unittest
from traits.api import HasTraits, Float


class mathOps(HasTraits):
    a = Float
    b = Float

    def add(self, a, b):
        self.a = a
        self.b = b

        return self.a +self.b

    def sub(self, a, b):
        self.a = a
        self.b = b

        return self.a -self.b

    def mul(self, a, b):
        self.a = a
        self.b = b

        return self.a*self.b

    def div(self, a, b):
        self.a = a
        self.b = b

        return self.a/self.b

class mathOpsTest(unittest.TestCase):
    obj = mathOps()

    def test_add(self):
        self.assertEqual(self.obj.add(1,1), 2)
        self.assertEqual(self.obj.add(1,2.0), 3.0)
        self.assertEqual(self.obj.add(3.0,1), 4.0)
        self.assertEqual(self.obj.add(5.0,6.0), 11.0)

    def test_sub(self):
        self.assertEqual(self.obj.sub(1,1), 0)
        self.assertEqual(self.obj.sub(1,2.0), -1.0)
        self.assertEqual(self.obj.sub(3.0,1), 2.0)
        self.assertEqual(self.obj.sub(4.0,8.0), -4.0)

    def test_mul(self):
        self.assertEqual(self.obj.mul(1,1), 1)
        self.assertEqual(self.obj.mul(1,2.0), 2.0)
        self.assertEqual(self.obj.mul(4.0,2), 8.0)
        self.assertEqual(self.obj.mul(3.0,7.0), 21.0)

    def test_div(self):
        self.assertEqual(self.obj.div(1,1), 1)
        self.assertEqual(self.obj.div(1.0,2), 0.5)
        self.assertEqual(self.obj.div(1,10.0), 0.1)
        self.assertEqual(self.obj.div(1.0,5.0), 0.2)

    @unittest.expectedFailure
    def test_vector_add(self):
        self.assertIsInstance(self.a, )
        self.assertEqual(self.obj.add([1,1],[1,1]),[2,2])

Popular posts from this blog

Farewell to Enthought

I started my professional career at Enthought , at the Pune office in India, on Feb 29, 2016. Over the course of eight long years, I spent time at the Austin office in the US, the Cambridge office in the UK, and I worked remotely from India. I was let go on March 27, 2024 . I had an unbelievably great time. I had three amazing mentors - Pankaj Pandey, Senganal Thirunavukkarasu, and Mark Dickinson. Pankaj mentored me in my first year at Enthought. I started paying attention to the craft of software after working with him. Senganal started mentoring me in my second year at Enthought, and continues to mentor me, even after the both of us have moved on from Enthought. He instilled professionalism in me, ensuring that the code I wrote produced precise scientific results, and that I tackled the known unknown aspects of a project first, to ensure timely communication about project progress. I was eager to manage people at the time and Senganal made me realize that I didn't want to manage ...
Read more

Arxiv author affiliations using Python

So, I wanted to get author affiliation information from papers on arXiv. arXiv provides with an API to bulk query their database and get information. Following that, I look for the attribute 'arxiv:affiliation' in the html data. Here's the code - import urllib from BeautifulSoup import BeautifulStoneSoup   url = 'http://export.arxiv.org/api/query?search_query=all:astro&start=0&max_results=1000'   data = urllib.urlopen(url).read() soup = BeautifulStoneSoup(data) #print(soup.prettify()) #list = soup.findAll('arxiv:affiliation') #for i in range(len(list)): #        print list[i].contents   test = [tag.string for tag in soup.findAll('arxiv:aiffiliation')] Now, the problem I'm having is that I'm getting affiliation of all authors which I want to split into sets of affiliations of authors of a paper, which I'm stuck on at the moment. Once I get that part, I can move on to the next part of this pet project, displaying these...
Read more

Elementary (particle physics), my dear Watson

Ground Control to Major Tom:  Shruti Patel checking in. Since my dear friend and fellow-physicist Rahul Poruri is homeward bound, and shall remain there for a week, I'm stepping in to continue his tradition of daily posts to Astronut . Even as I write, I'm not quite sure what this post is going to be about, so please forgive me for occasional rants and digressions.  By the way Rahul, I totally resent you for the name of this blog- I'm never going to start my own blog because there's no way I'll come up with a name as cool as Astronut! For now, I shall try and be happy with being a guest writer! Before I begin, a little bit on who I am and what I do; so that you can trust that my general views on science- particle physics in particular- are not entirely baseless. I graduated with a masters in Physics from IIT Madras in July this year, and I'm currently working towards (an eventual) PhD with the Theory Group at the Deutsches Electronen-Synchrotron (DESY)...
Read more