Simple Calculator in Python Console.

To be able to perform simple operations using a Python script by writing the equations.

A calculator is something used for making mathematical calculations, in particular a small electronic device with a keyboard and a visual display. The purpose of this project is performing simple calculations on a Python console.

import re
print("Simple Calculator")

previous = 0
run = True

def performMath():
    global run
    global previous
    equation = ""
    if previous == 0:
        equation = input("Enter equation:")
    else:
        equation = input(str(previous))


    if equation == "quit":
        print("Goodbye")
        run = False
    elif equation == "clear":
        previous = 0
    else:
        equation = re.sub('[a-zA-Z,.:()]','',equation)

        if previous == 0:
            previous = eval(equation)
        else:
            previous = eval(str(previous) + equation)

while run:
    performMath()