Change your lambda to lambda i=i: self.open_this(i).

This may look magical, but here's what's happening. When you use that lambda to define your function, the open_this call doesn't get the value of the variable i at the time you define the function. Instead, it makes a closure, which is sort of like a note to itself saying "I should look for what the value of the variable i is at the time that I am called". Of course, the function is called after the loop is over, so at that time i will always be equal to the last value from the loop.

Using the i=i trick causes your function to store the current value of i at the time your lambda is defined, instead of waiting to look up the value of i later.

Bumsfeld, you saved me! · I encountered the following problem in my code that displays the date in boxes for each day of the current week, and allows scheduling events for each day. · for i in range(7): · date = getDate(i) #This returns the date for each box in the row. · button = tk.Button(row) · button.configure(text=date)#This works fine for assigning text to the buttons. Each date value is unique for each button. · button.configure(command=lambda: createEvent(date)) #This does not work, because the function does not pass unique date values in the argument. Every button passes the same date value. · button.pack() · The createEvent()creates a new window to enter in event details for a particular date. However, createEvent(date) always passes the last date value for every box. Thus, even though I clicking on Monday's box (3/5/2012), the createEvent() still uses Sunday's date (3/11/2012). Instead of creating new function objects, tkinter always refers back to the original function object and updates it. This is not expected behavior, especially since the "command" attribute is the only tkinter attribute I have found that behaves like this. · However, it is solvable by borrowing from bumsfeld. Create the lambda argument outside of the tkinter argument: · action = lambda: createEvent(date) #Does not work · action = lambda x = date: createEvent(x) #This does work · button.configure(command=action) · As a follow up, can anyone point me to a resource that explains why Tkinter/Python behaves like this?

lambda: button_click((x, y), current_fleet) doesn't create a closure over x and y because they're not local names, they're global names (defined in top-level scope.) To create a closure, the name has to be defined in a local scope: def lambda_maker(x, y): return lambda: button_click((x, y), current_fleet) for x in range(10): #use this as row count for y in range(10): Button(root, [...], command=lambda_maker(x, y))

Define a function to print the contents of one sheet, taking the sheet number as an argument. Then, use functools.partial to associate a command with each button:

def print_sheet(sheet_number):
    ...

for i in range(0, num_sheets):
    an_sheet = ttk.Button(..., command = partial(print_sheet, i))
    ...

Here's a short but complete example of creating buttons in a loop:

import tkinter as tk
from tkinter import ttk
from functools import partial

root = tk.Tk()

def print_sheet(i):
    print("printing sheet %d" % i)

for i in range(0, 5):
    button = ttk.Button(root, text="Button %d" % i,
                        command=partial(print_sheet, i))
    button.pack()

root.mainloop()

Readability

• place constants at the top of your script with uppercase letters, according to PEP8
• don't exceed the maximum line length of 78 characters, according to PEP8
• add extra white space to align and group variables (it doesn't cost you anything, since python is an interpreted language)

Shrinking code

• use conditional assignment instead of if and else blocks

Efficiency

• just store variables that are used, unlike unopened_safe_tiles
• don't create multiple lambda expressions that do the same thing, instead create one and use it for both
• don't look up the same variable multiple times, store it instead. Unlike data_array[row][column]
• do not hard code every option, when they are all the same, use a dictionary instead
• For every click event and button command you call create_game_gui() which creates a new layer of buttons on top of the old ones, instead configure existing ones!

Yes, it is possible.

The following example creates a window with a reset button; upon clicking reset, a frame is populated with buttons corresponding to a random number of buttons chosen randomly from possible subjects. Each button has a command that calls a display function that redirects the call to the proper topic, which, in turn prints the name of its topic to the console, for simplicity of the example. You could easily create functions/classes corresponding to each topic, to encapsulate more sophisticated behavior.

Adding subjects, is as simple as adding a key-value pair in SUBJECTS

Pressing reset again, removes the current button and replaces them with a new set chosen randomly.

import random
import tkinter as tk
from _tkinter import TclError


SUBJECTS = {'Maths': lambda:print('Maths'), 
            'Physics': lambda:print('Physics'),
            'Chemistry': lambda:print('Chemistry'),
            'Biology': lambda:print('Biology'),
            'Astronomy': lambda:print('Astronomy'),
            'Petrology': lambda:print('Petrology'),}

topics = []


def topic_not_implemented():
    print('this topic does not exist')


def get_topics():
    """randomly creates a list of topics for this example
    """
    global topics
    topics = []
    for _ in range(random.randrange(1, len(SUBJECTS))):
        topics.append(random.choice(list(SUBJECTS.keys())))
    return topics


def reset_topics():
    global topics_frame

    try:
        for widget in topics_frame.winfo_children():
            widget.destroy()
        topics_frame.forget()
        topics_frame.destroy()
    except UnboundLocalError:
        print('error')
    finally:
        topics_frame = tk.Frame(root)
        topics_frame.pack()
    for topic in get_topics():
        tk.Button(topics_frame, text=topic, command=lambda topic=topic: display(topic)).pack()


def display(topic):
    """redirects the call to the proper topic
    """
    SUBJECTS.get(topic, topic_not_implemented)()


root = tk.Tk()
reset = tk.Button(root, text='reset', command=reset_topics)
reset.pack()
topics_frame = tk.Frame(root)
topics_frame.pack()
root.mainloop()

You were almost there. See below matter being resolved as you need a lambda to pass the btn_nr to the function action. By the way there is no need for int()

import tkinter as tk

window = tk.Tk()
window.geometry("300x150")
window.title("Tic Tac Toe")


def action(button):

    if btns[button].cget('text') == '-':
        btns[button].configure(text='X')

    else:
        btns[button].configure(text='-')


btn_nr = -1
btns = []

for x in range(1, 4):

    for y in range(1, 4):

        btn_nr += 1
        print(btn_nr)

        btns.append(tk.Button(text='-', command=lambda x=btn_nr: action(x)))
        btns[btn_nr].grid(row=x, column=y)

exit_button = tk.Button(text='Exit Game', command=window.destroy)
exit_button.grid(row=4, column=1, columnspan=15)

window.mainloop()

I changed the action function a little to make it toggle between 'X' and '-'.