Number Logic and Unit Testing with PyTest

by Eric Sales De Andrade (9 May 2022)

This is an exercise to find 3 numbers in a list whose sum totals a pre-defined value.

The solution is written in Python 3.8.5 and tested using the pytest module. Below are instructions how to setup your environment in the How To Run section.

Repo

The Repo contains

1. Python Module number_logic containing a script number_logic.py with the core logic with clear explanation of each function.
2. Input files containing data in the number-logic/number_logic/src/input folder.
3. Unit tests (functionality and exception/error handling checks) under the tests folder.

How To Run

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Step 1 - Prepare your local environment

Install Python and Virtual Environment

As a first step you'll need to prepare a Python environment.

Mac OS X comes pre installed with Python 2.7, but you'll need to upgrade to Python 3.8.5

You can do this with Anaconda (useful for creating a virtual environment) or just install it directly from the web. This link may be useful - https://python.land/installing-python

Follow these instructions for creating a Virtual Environment with Anaconda - https://www.geeksforgeeks.org/set-up-virtual-environment-for-python-using-anaconda/

Install Requirements

The code uses the pytest module so you'll need to install it via pip. To install pip kindly follow the instructions here - https://www.makeuseof.com/tag/install-pip-for-python/

Once you've installed python and pip please navigate to the Root Directory Wayflyer_ESDA and run the below command

pip install -r requirements.txt

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Step 2 - Run Module number_logic

From the Root Directory run

python number_logic

You should get a similar response as below

Number Class Initialised!
Reading Input File from /Users/ericsda/PycharmProjects/Wayflyer_ESDA/num_logic/src/input/input1_short_version.txt
Valid File found
The 3 numbers that sum up to 2020 are [979, 366, 675]
The multiplication of the 3 numbers is 241861950
241861950

Now lets run the Unit Test ###---------------------------------------------

Step 3 - Run Unit Tests

pytest ./tests/unit/test_number_logic.py -v -s

If the tests pass, you should get a response

============================================================================================ test session starts ============================================================================================
platform darwin -- Python 3.8.5, pytest-6.1.1, py-1.9.0, pluggy-0.13.1 -- /usr/local/anaconda3/envs/eric_dev/bin/python
cachedir: .pytest_cache
rootdir: /Users/ericsda/PycharmProjects/Wayflyer_ESDA
collected 7 items                                                                                                                                                                                           

tests/test_number_logic.py::test_read_input_file PASSED                                                                                                                                               [ 14%]
tests/test_number_logic.py::test_read_input_file_exception PASSED                                                                                                                                     [ 28%]
tests/test_number_logic.py::test_convert_str_int PASSED                                                                                                                                               [ 42%]
tests/test_number_logic.py::test_convert_str_int_exception PASSED                                                                                                                                     [ 57%]
tests/test_number_logic.py::test_check_sum PASSED                                                                                                                                                     [ 71%]
tests/test_number_logic.py::test_multiply_values PASSED                                                                                                                                               [ 85%]
tests/test_number_logic.py::test_multiply_values_exception PASSED                                                                                                                                     [100%]

============================================================================================= 7 passed in 0.02s =============================================================================================

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Congratulations you've run and tested the code successfully

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