Created a simple GUI to get myself started with TkInter!

[bixitz]

Hello friends, I have created this simple GUI using TkInter. Am I doing it right?

Here is the link to my code

import tkinter as tk
from tkinter import messagebox

class myApp:
    def __init__(self):
        self.root = tk.Tk()
        self.e1 = tk.StringVar()
        self.e2 = tk.StringVar()
        self.e3 = tk.StringVar()
        label1 = tk.Label(self.root, text='Price:')
        label2 = tk.Label(self.root, text='Discount:')
        label3 = tk.Label(self.root, text='%')
        label4 = tk.Label(self.root, text='Amount:')
        entry1 = tk.Entry(self.root, textvariable=self.e1)
        entry2 = tk.Entry(self.root, textvariable=self.e2)
        entry3 = tk.Entry(self.root, textvariable=self.e3, state='readonly')
        btn1 = tk.Button(self.root, text='Calculate',command=button_click)

        label1.grid(row=0,column=0,padx=(10,5),pady=(10,5),sticky=tk.W)
        entry1.grid(row=0,column=1,padx=(5,5),pady=(10,5))
        label2.grid(row=1,column=0,padx=(10,5),pady=(5,5),sticky=tk.W)
        entry2.grid(row=1,column=1,padx=(5,5),pady=(5,5))
        label3.grid(row=1,column=2,padx=(5,10),pady=(5,5))
        btn1.grid(row=2,column=1,padx=(5,5),pady=(5,5),sticky=tk.W)
        label4.grid(row=3,column=0,padx=(10,5),pady=(5,10),sticky=tk.W)
        entry3.grid(row=3,column=1,padx=(5,5),pady=(5,10),sticky=tk.W)
        self.root.resizable(False,False)
        self.root.title('Discount App')

def button_click():
    try:
        price = float(app.e1.get())
        discount = float(app.e2.get())
    except:
        messagebox.showwarning('Invalid Input','Please enter numbers only.')
    else:
        amount = price*(1-discount/100)
        app.e3.set(str(f'{amount:0.2f}'))

app = myApp()
app.root.mainloop()

[buran]

Please, post your code in python tags here. If you want to promote your blog - let us know and it may be included in the designated thread after review.

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OK, I will post your code for you this time

[nilamo]

Am I doing it right?

If that's a request for suggestions, then...

1) You don't follow PEP8 for naming or formatting. For code you intend to share, following it is very helpful: https://www.python.org/dev/peps/pep-0008/ If you check pip, there's a program called pylint which will read your file, and let you know how you can improve it.
Here's the first few lines when run against your program:

>pylint spam.py
************* Module spam
spam.py:3:0: C0303: Trailing whitespace (trailing-whitespace)
spam.py:17:52: C0326: Exactly one space required after comma
        btn1 = tk.Button(self.root, text='Calculate',command=button_click)
                                                    ^ (bad-whitespace)
spam.py:18:0: C0303: Trailing whitespace (trailing-whitespace)
spam.py:19:25: C0326: Exactly one space required after comma
        label1.grid(row=0,column=0,padx=(10,5),pady=(10,5),sticky=tk.W)
                         ^ (bad-whitespace)

2) On line 38, you have this: app.e3.set(str(f'{amount:0.2f}')). There's no reason to call str() on a string. It's already a string.

[bixitz]

Teaching programming for 2 decades doesn't mean I cannot learn Python as a new language. No, I don't want to promote my blog. I just wanted to share only to those who are interested to see. That's why I had included a picture of the app, so that people who are not interested need not waste their time.

Anyways, Thanks.

[buran]

So, everything is fine - your post is in the right sub-forum, the code is here to be seen and you will get bunch of good advise