Hello world 👋🏻 my name is Francisco, fcoterroba on the Internet and today I’m bringing you a post where I’m going to explain, as I always do, explaining line by line, how to program one of the most basic projects in any programming language, a calculator!
Before we start squeezing our brains 🧠 to program this game, I remind you that a couple of weeks ago I uploaded to my YouTube channel a video where I explain how to install a smart 💡 light bulb with which you can change color, turn off or on with voice and/or mobile, reduce or increase its intensity, etc. Also, you have it ready in LESS than 3 MINUTES ❗ In the description you also find some other surprise 😏 You can see it (and subscribe) here 👇🏻
Before starting to program with Python, you must have it installed correctly on your operating system. For this I recommend reading the official documentation available in English here.
Now yes, let’s begin
GAME IN THE COMMAND LINE
First, I want to show you in a simple gif, what you’re going to end up doing when you finish reading this post! 👇🏻
You like it, right? Well keep reading! 👀
The first thing we must do is open our favorite IDE (in my case it’s Visual Studio Code)
Then, we must create the two variables that, a priori, we’ll know we’re going to need, which are the variables to store the numbers that the user will insert.
In Python it’s not necessary to specify what type the variable will be (Char, float, integer,…), unlike many other programming languages since, Python 🐍, will automatically understand the variable type according to what we store in it.
For this project (and for almost all, really) I like to import the time (import time) ⌚ package since, I like to set a few seconds to facilitate screen reading for the user. Its use is simply by writing time.sleep(x) changing x for a certain number, in seconds.
Comments in Python are written by putting the symbol # at the beginning of the line
With print, just like in almost all programming languages, we’re going to write to the screen ✍🏻.
Well, after explaining all that previously, commenting some lines of code, importing the necessary packages and making a presentation to the program, we’ll have something like this:
#Calculator in CMD by fcoterroba.com
import time
print("Hello! Welcome to the calculator written in Python and developed by fcoterroba")
time.sleep(1)
print("You can find more interesting codes like this one on my website")
print(f"www.fcoterroba.com\nNow yes, let's begin: ")
time.sleep(0.8)
With this we’ll have created a very fast, interesting and minimalist main screen.
We need, now, to ask the user to write the two numbers they’ll want to work with additions, multiplications, subtractions,…
For this we must create the variable name followed by an input, converted to int, since, by default input collects values and stores them in text format.
numero1 = int(input("Tell me the first number: "))
numero2 = int(input(f"Good! Now tell me the second number: "))
print(f"Okay, you've chosen {numero1} and {numero2}")
time.sleep(1)
Now that we already have the numbers stored in variables, we must ask the user what type of calculation they want to perform between both and, to finish, perform a series of if/else conditions to find out the pressed key.
simbolo = input(f"What do you want to do with these numbers? (Write the first letter)\n -Add\n -Subtract\n -Multiply\n -Divide\n")
if simbolo == 'a' or simbolo == "A":
print(f"{numero1} + {numero2} =",(numero1+numero2))
elif simbolo == 's' or simbolo == "S":
print(f"{numero1} - {numero2} =",(numero1-numero2))
elif simbolo == 'm' or simbolo == "M":
print(f"{numero1} * {numero2} =",(numero1*numero2))
elif simbolo == 'd' or simbolo == "D":
print(f"{numero1} / {numero2} =",(numero1/numero2))
else:
print(f"You haven't written any correct letter\nA|a to add S|s to subtract M|m to multiply or D|d to divide")
And with this and a cake 🎂, we’re done!
Now, to you, little friend, I propose two points to complete in this project:
- First, you must improve the calculator we’ve made, in terms of code organization, having clean code and not being so much spaghetti code 🍝. You must use functions, place the code correctly in its place, etc.
- Finally, you must transfer this calculator to a graphical interface or GUI. The most used in Python 🐍 is TKinter, but you can use any other package you want like PySimpleGUI, Kivi, PySide2, etc. The options are wide!
And that’s been everything for today guys, I hope you liked the post, approaching programming easily and simply. Don’t forget to follow me on Twitter, Facebook, Instagram and LinkedIn. See you next week!