How To Make A Simple Calculator in Python? A Complete Guide

The Program For Calculator In Python is written in Python programming language, In this article I will teach you how to make a simple calculator in Python.

Program For Calculator In Python: Project Information

Python has a design philosophy that emphasizes code readability. That’s why Python is very smooth to use mainly for novices who just started programming.

It is very smooth to research the syntax emphasizes clarity and it could reduce time consuming in developing.

About The Project Calculator in Python

This Program was designed in Calculator In Python GUI or Graphical User Interface using Calculator In Python Tkinter.

This article also includes the downloadable Calculator Python Code for free.✅

To start creating the Program For Calculator In Python, make sure that you have PyCharm IDE installed on your computer.

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Steps on How To Make A Calculator in Python with Example

Calculator in Python Code Explanations

1. Import Module

The code given below is for importing the module.

from tkinter import*

This piece of code is importing the Tkinter module for the design of this project.

2. GUI

The code given below is for the design or GUI of this project.

def fCalc(src, side):
    appObj = Frame(src, borderwidth=4, bd=2,bg = "#cccccc")
    appObj.pack(side=side, expand=YES, fill=BOTH)
    return appObj

def button(src, side, text, command=None):
    appObj = Button(src, text=text, command=command)
    appObj.pack(side=side, expand=YES, fill=BOTH)
    return appObj

class app(Frame):
    def __init__(self, root = Tk(), width=364, height=425):
        Frame.__init__(self)
        self.option_add("*Font", 'arial 20 bold')
        self.pack(expand=YES, fill=BOTH)
        self.master.title("Simple Calculator")
        screen_width = root.winfo_screenwidth()
        screen_height = root.winfo_screenheight()
        x = (screen_width/2) - (width/2)
        y = (screen_height/2) - (height/2)
        root.geometry('%dx%d+%d+%d' % (width, height, x, y))
        display = StringVar()
        Entry(self, relief= RIDGE,      
                    textvariable=display, state=DISABLED, justify='right', bd=20, bg="silver").pack(side=TOP, expand=YES,
                            fill=BOTH)
        clrChar = "Clear"
        button(self, TOP, clrChar, lambda appObj=display, i=clrChar: appObj.set(''))


        for btnNum in ("789/", "456*", "123-", "0.+"):

            FunctionNum = fCalc(self, TOP)
            for fEquals in btnNum:
                button(FunctionNum, LEFT, fEquals,
                        lambda appObj=display, i=fEquals: appObj.set(appObj.get() + i))
                EqualsButton = fCalc(self, TOP)
                
        for fEquals in "=":
            if fEquals == "=":
                btnEquals = button(EqualsButton, LEFT, fEquals)
                btnEquals.bind('<ButtonRelease-1>',
                                lambda e, s=self, appObj=display: s.result(appObj), "+")
            else:
                btnEquals = button(EqualsButton, LEFT, fEquals,
                        lambda appObj=display, s=" %s "%fEquals: appObj.set(appObj.get()+s))

In this module is the code for the design of this project.

3. Display Result

The code given below is for displaying the result.

    def result(self, display):
        try:
            display.set(eval(display.get()))
        except:
            display.set("UNDEFINED")

In this module which displays the result you’ve entered in the text field, with conditioning.

4. Complete Source Code

from tkinter import*

def fCalc(src, side):
    appObj = Frame(src, borderwidth=4, bd=2,bg = "#cccccc")
    appObj.pack(side=side, expand=YES, fill=BOTH)
    return appObj

def button(src, side, text, command=None):
    appObj = Button(src, text=text, command=command)
    appObj.pack(side=side, expand=YES, fill=BOTH)
    return appObj

class app(Frame):
    def __init__(self, root = Tk(), width=364, height=425):
        Frame.__init__(self)
        self.option_add("*Font", 'arial 20 bold')
        self.pack(expand=YES, fill=BOTH)
        self.master.title("Simple Calculator")
        screen_width = root.winfo_screenwidth()
        screen_height = root.winfo_screenheight()
        x = (screen_width/2) - (width/2)
        y = (screen_height/2) - (height/2)
        root.geometry('%dx%d+%d+%d' % (width, height, x, y))
        display = StringVar()
        Entry(self, relief= RIDGE,      
                    textvariable=display, state=DISABLED, justify='right', bd=20, bg="silver").pack(side=TOP, expand=YES,
                            fill=BOTH)
        clrChar = "Clear"
        button(self, TOP, clrChar, lambda appObj=display, i=clrChar: appObj.set(''))


        for btnNum in ("789/", "456*", "123-", "0.+"):

            FunctionNum = fCalc(self, TOP)
            for fEquals in btnNum:
                button(FunctionNum, LEFT, fEquals,
                        lambda appObj=display, i=fEquals: appObj.set(appObj.get() + i))
                EqualsButton = fCalc(self, TOP)
                
        for fEquals in "=":
            if fEquals == "=":
                btnEquals = button(EqualsButton, LEFT, fEquals)
                btnEquals.bind('<ButtonRelease-1>',
                                lambda e, s=self, appObj=display: s.result(appObj), "+")
            else:
                btnEquals = button(EqualsButton, LEFT, fEquals,
                        lambda appObj=display, s=" %s "%fEquals: appObj.set(appObj.get()+s))

    def result(self, display):
        try:
            display.set(eval(display.get()))
        except:
            display.set("UNDEFINED")

if __name__ == '__main__':
    app().mainloop()

Output:

Downloadable Source Code

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Summary

The Program For Calculator In Python is written in Python programming language, Python has a design philosophy that emphasizes code readability.

That’s why Python is very smooth to use mainly for novices who just started programming. It is very smooth to research the syntax emphasizes clarity and it could reduce time consuming in developing.

The project file contains the python script (simple_calculator.py). This article can help beginners in developing Python programming language, and also develop their skills in programming because the syntax and the logic in this Python programming is easy to catch up and understand.

Angel Jude Suarez

Full-Stack Developer at PIES IT Solution

Focuses on Python development, machine learning, and AI integration. Has built production AI systems including OpenAI Whisper integration for medical transcription and GPT-4o-powered diagnosis assistance. Strong background in pandas, scikit-learn, and TensorFlow.

Expertise: Python · PHP · Java · VB.NET · ASP.NET · Machine Learning · AI Integration · OpenCV · Django · CodeIgniter  · View all posts by Angel Jude Suarez →