Help! ! ! How do I raise error in the user's input to enter only letters not numbers?

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I was making a simple Tk GUI which greets the user's input name... I need to raise a Input Error when the user would enter a number. The user must enter LETTERS only. Based on what I have tried, only the first name input was being checked not with the last name. What do I add or edit?

Thank you in advanceee..!!

What I have tried:

import tkinter
from tkinter import *
import tkinter.messagebox

root = Tk()
root.geometry("300x130")
root.resizable(0, 0)
root.title("Greeting User")

def button_enter():
    while True:
        item1 = (input1.get())
        item2 = (input2.get())
        name = (item1 + " " + item2)
        for a in name:
            if (a.isalpha() or a.isspace()) or (a.isalpha() and a.isspace()) and (name.isalpha() and name.isspace()):
                greeting = Label(root, text="Hello, " + name + "!")
                greeting.grid(column=1, row=3)
                return True
            else:
                tkinter.messagebox.showinfo('Input Error', 'Numerical value detected. Try again.')
                return False


label1 = Label(root, text="First Name:").grid(row=0)
label2 = Label(root, text="Last Name:").grid(row=1)

input1 = Entry(root, width=30, justify=CENTER)
input1.grid(column=1, row=0)
input1.get()

input2 = Entry(root, width=30, justify=CENTER)
input2.grid(column=1, row=1)
input2.get()

myButton = Button(root, width=10, text="Enter", command=button_enter)
myButton.grid(column=0, row=3)

root.mainloop()

Posted 27-May-21 20:34pm

lil_mint

Updated 27-May-21 20:46pm

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OriginalGriff · Accepted Answer · 2021-05-27T20:46:00

OR is a condition that combines two boolean inputs:

A = B OR C

if they are both false, it evaluates to false. Otherwise, it evaluates to true.
So if either B or C is true, then A is true regardless of the value of the other.
So in your code:

        for a in name:
            if (a.isalpha() or a.isspace()) or (a.isalpha() and a.isspace()) and (name.isalpha() and name.isspace()):
...
                return True

If the first character in the input is alphabetic, then your function returns True - it does not even look at any other characters and the loop is terminated.
Move the return True to after the loop, and simplify your condition: most of it is irrelevant!