Calculator app – Python Mini Project with Code Tutorial

How to make calculator in python with basic and guide walk through is here – Python Mini Project with code tutorial. If you want you resume to become eye catcher start making python project. Pythongdb is here to help those who are willing to create project from beginner level.

Here we are going to se Prerequisites , Code, Output , Screen shot.

Prerequisites

• Python3
• tkinter

Code to Create Calculator

# -*- coding: utf-8 -*-
from tkinter import Tk, END, Entry, N, E, S, W, Button
from tkinter import font
from tkinter import Label
from functools import partial


def get_input(entry, argu):
    entry.insert(END, argu)


def backspace(entry):
    input_len = len(entry.get())
    entry.delete(input_len - 1)


def clear(entry):
    entry.delete(0, END)


def calc(entry):
    input_info = entry.get()
    try:
        output = str(eval(input_info.strip()))
    except ZeroDivisionError:
        popupmsg()
        output = ""
    clear(entry)
    entry.insert(END, output)


def popupmsg():
    popup = Tk()
    popup.resizable(0, 0)
    popup.geometry("120x100")
    popup.title("Alert")
    label = Label(popup, text="Cannot divide by 0 ! \n Enter valid values")
    label.pack(side="top", fill="x", pady=10)
    B1 = Button(popup, text="Okay", bg="#DDDDDD", command=popup.destroy)
    B1.pack()


def cal():
    root = Tk()
    root.title("Calc")
    root.resizable(0, 0)

    entry_font = font.Font(size=15)
    entry = Entry(root, justify="right", font=entry_font)
    entry.grid(row=0, column=0, columnspan=4,
               sticky=N + W + S + E, padx=5, pady=5)

    cal_button_bg = '#FF6600'
    num_button_bg = '#4B4B4B'
    other_button_bg = '#DDDDDD'
    text_fg = '#FFFFFF'
    button_active_bg = '#C0C0C0'

    num_button = partial(Button, root, fg=text_fg, bg=num_button_bg,
                         padx=10, pady=3, activebackground=button_active_bg)
    cal_button = partial(Button, root, fg=text_fg, bg=cal_button_bg,
                         padx=10, pady=3, activebackground=button_active_bg)

    button7 = num_button(text='7', bg=num_button_bg,
                         command=lambda: get_input(entry, '7'))
    button7.grid(row=2, column=0, pady=5)

    button8 = num_button(text='8', command=lambda: get_input(entry, '8'))
    button8.grid(row=2, column=1, pady=5)

    button9 = num_button(text='9', command=lambda: get_input(entry, '9'))
    button9.grid(row=2, column=2, pady=5)

    button10 = cal_button(text='+', command=lambda: get_input(entry, '+'))
    button10.grid(row=4, column=3, pady=5)

    button4 = num_button(text='4', command=lambda: get_input(entry, '4'))
    button4.grid(row=3, column=0, pady=5)

    button5 = num_button(text='5', command=lambda: get_input(entry, '5'))
    button5.grid(row=3, column=1, pady=5)

    button6 = num_button(text='6', command=lambda: get_input(entry, '6'))
    button6.grid(row=3, column=2, pady=5)

    button11 = cal_button(text='-', command=lambda: get_input(entry, '-'))
    button11.grid(row=3, column=3, pady=5)

    button1 = num_button(text='1', command=lambda: get_input(entry, '1'))
    button1.grid(row=4, column=0, pady=5)

    button2 = num_button(text='2', command=lambda: get_input(entry, '2'))
    button2.grid(row=4, column=1, pady=5)

    button3 = num_button(text='3', command=lambda: get_input(entry, '3'))
    button3.grid(row=4, column=2, pady=5)

    button12 = cal_button(text='*', command=lambda: get_input(entry, '*'))
    button12.grid(row=2, column=3, pady=5)

    button0 = num_button(text='0', command=lambda: get_input(entry, '0'))
    #button0.grid(row=5, column=0, columnspan=2, padx=3, pady=5, sticky=N + S + E + W)
    button0.grid(row=5, column=0,  pady=5)

    button13 = num_button(text='.', command=lambda: get_input(entry, '.'))
    button13.grid(row=5, column=1, pady=5)

    button14 = Button(root, text='/', fg=text_fg, bg=cal_button_bg, padx=10, pady=3,
                      command=lambda: get_input(entry, '/'))
    button14.grid(row=1, column=3, pady=5)

    button15 = Button(root, text='<-', bg=other_button_bg, padx=10, pady=3,
                      command=lambda: backspace(entry), activebackground=button_active_bg)
    button15.grid(row=1, column=0, columnspan=2,
                  padx=3, pady=5, sticky=N + S + E + W)

    button16 = Button(root, text='C', bg=other_button_bg, padx=10, pady=3,
                      command=lambda: clear(entry), activebackground=button_active_bg)
    button16.grid(row=1, column=2, pady=5)

    button17 = Button(root, text='=', fg=text_fg, bg=cal_button_bg, padx=10, pady=3,
                      command=lambda: calc(entry), activebackground=button_active_bg)
    button17.grid(row=5, column=3, pady=5)

    button18 = Button(root, text='^', fg=text_fg, bg=cal_button_bg, padx=10, pady=3,
                      command=lambda: get_input(entry, '**'))
    button18.grid(row=5, column=2, pady=5)
    def quit():
        exit['command'] = root.quit()
    exit = Button(root, text='Quit', fg='white', bg='black', command=quit, height=1, width=7)
    exit.grid(row=6, column=1)

    root.mainloop()


if __name__ == '__main__':
    cal()

Our Calculator you can Customise it by changing colour etc.

In this article we build Python mini project for Calculator.

I hope you all will enjoy the process of learning from next we will be posting video tutorial for that also .