First python project — Basic Calculator

Photo by Amol Tyagi on Unsplash

As a part of learning, I started coding in python. My kids are just curious about what am I learning and wanted to test my code, so I started with basic calculator.

Core Concepts :

• Arithmetic Operators
• Logical Operators
• Conditional Statements
• Functions

Variables :

Three variables used here are for accepting inputs from the user.

They are, mode_of_operation , first_number and second_number.

mode_of_operation = input("""Enter the Operation you want to perform : "
+ for Addition
- for Subtraction
* for Multiplication
/ for Division
% for Modulo
** for Exponent  :  """)
first_number = input("Enter first number : ")
second_number = input("Enter second number : ")

Functions :

Functions defined are,

def is_blank():

def is_digit():

def basic_calculator(n):

Function is_blank() is to check whether input field is maintained or left blank.

If any of the input is blank, this function returns False otherwise True.

def is_blank():
    if (first_number != "") and (second_number != ""):
        is_blank = True
    else:
        is_blank = False
    return is_blank

In is_digit() function variable_name.is_digit() method is used, that returns True if all the characters are digits, otherwise False.

def is_digit():
    if (first_number.isdigit()) and (second_number.isdigit()):
        is_digit = True
    else:
        is_digit = False
    return is_digit

In def basic_calculator(n),mode_of_operation is passed as an argument and depending on selection, conditional loop will execute. If valid operator is not entered, final else block statement is executed and prints: “Please enter valid operation”

def basic_calculator(n):
    if n == "+":
        if is_blank() and is_digit():
            result = int(first_number) + int(second_number)
        else:
            result = "Please enter valid inputs"
    elif n == "-":
        if is_blank() and is_digit():
            result = int(first_number) - int(second_number)
        else:
            result = "Please enter valid inputs "
    elif n == "*":
        if is_blank() and is_digit():
            result = int(first_number) * int(second_number)
        else:
            result = "Please enter valid inputs"
    elif n == "/":
        if is_blank() and is_digit():
            result = int(first_number) / int(second_number)
        else:
            result = "Please enter valid inputs"
    elif n == "%":
        if is_blank() and is_digit():
            result = int(first_number) % int(second_number)
        else:
            result = "Please enter valid inputs"
    elif n == "**":
        if is_blank() and is_digit():
            result = int(first_number) ** int(second_number)
        else:
            result = "Please enter valid inputs"
    else:
        result = "Please select valid operation "
    print(result)

Finally , call the function with mode_of_operation as argument.

basic_calculator(mode_of_operation)

Output :

Scenario 1 -

mode_of_operation : +

first_number : 50

second_number : 50

Enter the Operation you want to perform : " 
+ for Addition 
- for Subtraction 
* for Multiplication 
/ for Division 
% for Modulo 
** for Exponent  :  + 
Enter first number : 50 
Enter second number : 50
100

Scenario 2 -

mode_of_operation : 5

first_number : 50

second_number : 50

Enter the Operation you want to perform : " 
+ for Addition 
- for Subtraction 
* for Multiplication 
/ for Division 
% for Modulo 
** for Exponent  :  5 
Enter first number : 50 
Enter second number : 50 
Please select valid operation

Scenario 3 -

mode_of_operation : *

first_number :

second_number : 50

Enter the Operation you want to perform : "
+ for Addition
- for Subtraction
* for Multiplication
/ for Division
% for Modulo
** for Exponent  :  *
Enter first number : 
Enter second number : 50
Please enter valid inputs

Scenario 4 -

mode_of_operation : *

first_number : kg

second_number : 50

Enter the Operation you want to perform : "
+ for Addition
- for Subtraction
* for Multiplication
/ for Division
% for Modulo
** for Exponent  :  *
Enter first number : kg
Enter second number : 50
Please enter valid inputs

Thanks for reading..!!