How to set the variablee in a button command to own button's text in a loop that creates multipule buttons?

Question

I have a loop that creates a button under a label that contains a list value:

def feed_page():

    feed = ["Cooking", "Sports", "Tv", "Fashion"] #let's say those are the list's values
    l = len(feed) - 1
    x = 0


    while l >=0:
        Label(app, text=feed[l]).grid(row=x, column=1)
        b = Button(app, text=feed[l])
        b.configure(command=lambda: print_button_pressed_text(b.cget('text')))
        b.grid(row=x+1, column=1)
        x += 2

*The list Feed length and values change every time the function feed_page() is called.

I want that every time a certain button is pressed, the print_button_pressed_text function will print out the text of that specific button that was pressed. (each button has his own unique number)

def print_button_pressed_text(num):
    print num

However, no matter what button I press, the function prints the Value 'Fashion' (the last value in the list..)

Do you have any idea what the problem is? and how can I fix it?

Asked By: mimi quarantine

||

Source

Answer 1

def print_button_pressed_text(num):
  def handler:
    return num;
  return handler;

UPD

The problem is that lambda functions look at the wrong button, only the last one since the loop doesn’t provide the right scope.

def make_button(text, row):
  b = Button(app, text=text)
  b.configure(command=lambda: print_button_pressed_text(b.cget('text')))
  b.grid(row=x+1, column=1)
  return b

while l >= 0:
  make_button(feed[l], x + 1)
  # ...

UPD2

Why does it happen? Please, check this out → https://louisabraham.github.io/articles/python-lambda-closures.html if you want to know more about scopes and closures.

Answered By: vitkarpov

Answer 2

Can’t you use the join function ?
Just define a function:

feed = ["Cooking", "Sports", "Tv", "Fashion"]
def print_the_list:
     global feed
     print(" ".join(feed))
print_the_list()

Then set this function as your button’s command. If you want to put , or ; or whatever you want between the elements, modify the ” ” into “,” or “;”

Answered By: Quantum Sushi

How to set the variablee in a button command to own button's text in a loop that creates multipule buttons?

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