Simple Calculator Module

Building a python package using simple calculator program

In this repo you will git to know :

• How to build a python program into package?
• How tp publish your package to PyPi repo?
• How to create unit test and automate testing for python program?
• How to check for code quailty and styling using pylint on python program?
• How to using GitHub Action :
  1. Publish Python Package
     • By GitHub Actions
     • Publish a Python Package to PyPI on release.
  2. Pylint
     • By GitHub Actions
     • Lint a Python application with pylint.
  3. Python application
     • By GitHub Actions
     • Create and test a Python application.
  4. Python package
     • By GitHub Actions
     • Create and test a Python package on multiple Python versions.

Program Structure

Displaying Interface Options

    # print the calculator interface
    print("Select operation::")
    print("0. Exit")
    print("1. Add (+) ")
    print("2. Subtract (-)")
    print("3. Multiply (*)")
    print("4. Divide (/)")

Interaction with users

    while True:    
        # take input from the user
        choice = input("Enter choice(0/1/2/3/4): ")
        
        # check if choice is one of the four options
        if choice in ('1', '2', '3', '4'):
            x = (input("Enter first number: "))
            y = (input("Enter second number: "))
            
            # creating object from class
            cal = Calculator(x, y)
        
        if choice == '1':
            print("Result: ",cal.add())
        elif choice == '2':
            print("Result: ",cal.sub())
        elif choice == '3':
            print("Result: ",cal.mul())
        elif choice == '4':
            print("Result: ",round(cal.div(),2))
        elif choice == '0':
            print("Exiting!!")
            break
        else:
            print("Invalid Input, please try again")

Class Definition

    class Calculator():
        '''
        Create a class and using a constructor to initialize values of that class.
        '''
        def __init__(self, x, y):
            self.x = float(x)
            self.y = float(y)
        # This methos add two nubers
        def add(self):
            return self.x + self.y
        # This methos subtracting two numbers
        def sub(self):
            return self.x - self.y

        # This methos multiplying two numbers
        def mul(self):
            return self.x * self.y  

        # This methos dividing two numbers
        def div(self):
            return self.x / self.y

Unit Testing

A Typical directory structure for running tests using pytest

Ref : stackoverflow

The best solution in my opinion is to use the unittest command line interface which will add the directory to the sys.path so you don't have to (done in the TestLoader class).

For example for a directory structure like this:

cal_project
├── calculator.py
└── test_calculator.py

You can just run:

$ cd new_project
$ python -m pytest test_antigravity

For a directory structure like yours:

new_project
├── antigravity
│   ├── __init__.py         # make it a package
│   └── antigravity.py
└── test
    ├── __init__.py         # also make test a package
    └── test_antigravity.py

And in the test modules inside the test package, you can import the antigravity package and its modules as usual:

# import the package
import antigravity

# import the antigravity module
from antigravity import antigravity

# or an object inside the antigravity module
from antigravity.antigravity import my_object

Running a single test module:

To run a single test module, in this case test_antigravity.py:

$ cd new_project
$ python -m unittest test.test_antigravity

Just reference the test module the same way you import it.

Running a single test case or test method:

Also you can run a single TestCase or a single test method:

$ python -m unittest test.test_antigravity.GravityTestCase
$ python -m unittest test.test_antigravity.GravityTestCase.test_method

Running all tests:

You can also use test discovery which will discover and run all the tests for you, they must be modules or packages named test*.py (can be changed with the -p, --pattern flag):

$ cd new_project
$ python -m unittest discover

This will run all the test*.py modules inside the test package.