PyQt4 - Button.connect() recieves always last iteration index

Question

Im doing a software with Python3.6, PyQt4 and SQlite3. The software consist in a number of students each of them with their data (unique id, name, surname, address, etc.) The GUI has a list menu, were the list of all the students is shown.

In the list itself, I iterate depending on how many students I have. The layout is made and it creates a name, and 2 QPushButtons (one to generate a PDF and other to delete the student data)

Here is an example

In my code, I have every "Generate a PDF" button of each student in the list on a python list, also for the "Delete student" buttons. My problem is when I give the buttons the .clicked.connect(function)

for i in range(0, len(self.list_menu.delete_button_list)):
    self.list_menu.delete_button_list[i].clicked.connect(
        lambda: self.delete_student_data(self.list_menu.id_list[i]))

For example, I have 3 students on the list, so button 1 should recieve id:1 self.delete_student_data(1), then button_2 with id=2 and button_3 with id:=3. But from what I've understood, what .connect() recieves does not execute, not until the button is actually clicked in this case. So at the moment .connect() is called, the value i is 3 in this example. Hence every button call the self.delete_student_data with id=3.

I see that there is no way to make this work like I pretend to.

Hope its clear the way I described it. Thanks!

Answer 1

I resolved the problem by using functools.partial module. As from what I understand, partial takes the argument of the function and 'freezes' it. Maybe someone knows better this whole behavior and can explain it better. Here is the documentation.

Now the code is the following:

for i in range(0, len(self.list_menu.delete_button_list)):
button = self.list_menu.delete_button_list[i]
button.clicked.connect(partial(self.delete_student_data, button))