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from tkinter import *

root = Tk()
Label(root, text = "Enter Number of columns").grid(row = 0, column = 0)
N = IntVar()
e_N = Entry(root, textvariable = N).grid(row = 0, column = 1)

# Put trace callbacks on the Entry IntVar
def create_rows(name, index, mode):
    rows = N.get()
    for i in range(rows):
        Entry(root).grid(row = i + 1, column = 0)

N.trace('w', create_rows)
# Setting the vars will trigger the trace
N.set(2)

mainloop()

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Exception in Tkinter callback
Traceback (most recent call last):
  File "/home/erich/anaconda3/lib/python3.7/tkinter/__init__.py", line 508, in get
    return self._tk.getint(value)
_tkinter.TclError: expected integer but got ""

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/erich/anaconda3/lib/python3.7/tkinter/__init__.py", line 1705, in __call__
    return self.func(*args)
  File "<ipython-input-120-42d7236d23c8>", line 10, in create_rows
    rows = N.get()
  File "/home/erich/anaconda3/lib/python3.7/tkinter/__init__.py", line 510, in get
    return int(self._tk.getdouble(value))
_tkinter.TclError: expected floating-point number but got ""

Code: Alles auswählen

    try:
        rows = N.get()
    except _tkinter.TclError: 
         " "

Code: Alles auswählen

from functools import partial
import tkinter as tk

def create_rows(name, index, mode, root=None, eingabe=None):
    try:
        rows = eingabe.get()
    except tk.TclError:
        pass
    else:
        for i in range(rows):
            tk.Entry(root).grid(row=i+1, column=0)

def main():
    root = tk.Tk()
    tk.Label(root, text="Enter Number of columns").grid(row=0, column=0)
    eingabe = tk.IntVar(root, 2)
    eingabe.trace('w', partial(create_rows, root=root, eingabe=eingabe))
    tk.Entry(root, textvariable=eingabe).grid(row=0, column=1)
    root.mainloop()

if __name__ == '__main__':
    main()