# Tk_entry_character_limit.py

# Tk_entry_character_limit.py

from Tkinter import *

limit = 5

Window = Tk()
Window.geometry("200x200+50+50") # heightxwidth+x+y

mainPanel = Canvas(Window, width = 200, height = 200) # main screen
mainPanel.pack()

entry_text = StringVar() # the text in  your entry
entry_widget = Entry(mainPanel, width = 20, textvariable = entry_text) # the entry
mainPanel.create_window(100, 100, window = entry_widget)

def character_limit(entry_text):
    if len(entry_text.get()) > 0:
        entry_text.set(entry_text.get()[:limit]) # char limit

entry_text.trace("w", lambda *args: character_limit(entry_text))