Tkinter Widget For Loop is typing in every Widget-CodePudding

I tried creating a widget for loop that would only allow one letter input, but I'm running into an issue where it creates text for every widget. I assume the issue lies with the "len" I used.

from tkinter import *
from pynput.keyboard import Key, Controller
root = Tk()

height = 6
width = 5

delta=0

entries = []

def limitSizeDay(*args):
    value = dayValue.get()
    if len(value) > 1: dayValue.set(value[:1])

dayValue = StringVar()
dayValue.trace('w', limitSizeDay)




for i in range(height): #Rows
  newrow = []
  for j in range(width): #Columns
    b = Entry(root, text="",width=2,font=('Arial', 40, 'bold'), textvariable=dayValue)
    b.grid(row=i, column=j)
    newrow.append(b)
  entries.append(newrow)


def getword(event):
    global b
    ass = b.get()
    print(ass)
    keyboard = Controller()
    keyboard.press(Key.tab)
    keyboard.release(Key.tab)

root.bind('<Return>', getword)

mainloop()

CodePudding user response：

No. The problem is that you have bound every Entry box to the same textvariable (dayValue). When you change that one variable, all of the boxes respond. I can't tell what you are really trying to achieve with this. If you want each box to have its own variable, then you need to create a LIST of StringVars, probably inside the loop so you get the same size.

CodePudding user response：

As Tim said the cause of your problem is binding the same StringVar to all of the Entry widgets. To make this work, you need to create a StringVar for each Entry in a loop:

for i in range(height): #Rows
  newrow = []
  for j in range(width): #Columns
    dayValue = StringVar()
    dayValue.trace('w', limitSizeDay)
    b = Entry(root, text="",width=2,font=('Arial', 40, 'bold'), textvariable=dayValue)
    b.var = dayValue # Prevent garbage collection (I think)
    b.grid(row=i, column=j)
    newrow.append(b)
  entries.append(newrow)

Then you need to change limitSizeDay to access the variable.

def limitSizeDay(var, *args):
    value = root.globalgetvar(var)
    if len(value) > 1: root.globalsetvar(var, value[:1])

The globalgetvar and globalsetvar methods allow you to get and set the variable respectively as the usual getvar and setvar don't work in this case.