Select and plot lists through checkbuttons (python, tkinter)

Question

Say I got a multidimensional list:

my_list = [[1,2,3,4,5], [2,3,4,5,6], [3,4,5,6,7]]

Now I want to create a GUI with Tkinter where one could check boxes to select which of these sub-lists should be plotted in a histogram. So for this example I imagine three checkboxes (labeled 0, 1, 2) and a Button "Show Histograms". Say I check boxes labeled 1 and 2 and press the "Show Histograms" Button, it should show the histograms of my_list[0]and my_list[1](preferably as subplots on one canvas). What would be the approach?

Answer 1

OOP Example:

Defines a class SubplotCheckbutton ..., inheriting from tk.Checkbutton.
Extends the tk.Checkbutton widget with:

• Named argument subplot=
• The required tk.Variable, here tk.IntVar
• A class method checked() which returns True/False according the checked state.

---

Reference:

• Correctly extend a tkinter widget using inheritance

• The Tkinter Checkbutton Widget

---

1. What do the arguments parentand **kwargs in the init method mean?
   Every Tkinter widget needs a parent. Therefore the first argument of all Tkinterwidgets class objects take the parent argument. A parent in Tkinter specifies in which widget your widget, here Checkbutton, are layouted.
   • class App(tk.Tk): => self
   • SubplotCheckbutton(self, ...
   • def __init__(..., parent, ...
   • super().__init__(parent, ... => tk.Checkbutton(parent)

---

**kwargs are shorted from known word arguments and is of type dict.
Here: text=str(i) and subplot=subplot

2. will be continued ...

---

import tkinter as tk


class SubplotCheckbutton(tk.Checkbutton):
    def __init__(self, parent, **kwargs):
        # Pop the 'subplot=' argument and save to class member
        self.subplot = kwargs.pop('subplot')

        # Extend this class with the required tk.Variable
        self.variable = tk.IntVar()

        # __init__ the inherited (tk.Checkbutton) class object
        # Pass the argument variable= and all other passed arguments in kwargs
        super().__init__(parent, variable=self.variable, **kwargs)

    # Extend this object with a checked() method
    def checked(self):
        # Get the value from the tk.Variable and return True/False
        return self.variable.get() == 1

Usage:

Note: No root, the class object App is the root object, therefore you have to use self as parent:

• SubplotCheckbutton(self, ...
• Button(self, ...

class App(tk.Tk):
    def __init__(self):
        super().__init__()

        my_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
        self.channels = []

        for i, subplot in enumerate(my_list):
            self.channels.append(SubplotCheckbutton(self, text=str(i), subplot=subplot))
            self.channels[-1].pack()

        tk.Button(self, text="Show Histograms", command=self.show).pack()

    def show(self):
        for channel in self.channels:
            if channel.checked():
                fig, ax = plt.subplots()
                y, x, _ = ax2.hist(channel.subplot, bins = 150)
                plt.show()


if __name__ == '__main__':
    App().mainloop()

Answer 2

root = Tk()

my_list = [[1,2,3,4,5], [2,3,4,5,6], [3,4,5,6,7]]

var = IntVar()
var2 = IntVar()
var3 = IntVar()

def show():
    

    if var.get() == 1: 
        fig, ax = plt.subplots()
        y, x, _ = ax.hist(my_list[0], bins = 150)
        

    if var2.get() == 1:
        fig2, ax2 = plt.subplots()
        y, x, _ = ax2.hist(my_list[1], bins = 150)
        

    if var3.get()    def checked(self):
        return self.variable.get() == 1

 == 1:
        fig3, ax3 = plt.subplots()
        y, x, _ = ax3.hist(my_list[2], bins = 150)
    
    plt.show()





button = Button(root, text = "Show Histograms", command = show).pack()

c = Checkbutton(root, text = 'first list', variable = var).pack()
c2 = Checkbutton(root, text = 'second list', variable = var2).pack()
c3 = Checkbutton(root, text = 'third list', variable = var3).pack()


root.mainloop()

UPDATE: I managed to write it more compact but it does not work like that:

my_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
varChannels = []
checkbuttonChannels = []

def show():
    for i in range(3):
        if varChannels[i] == 1:
            fig, ax = plt.subplots()
            y, x, _ = ax2.hist(my_list[i], bins = 150)
            plt.show()



for _ in range(3):
    varChannels.append(IntVar())
    checkbuttonChannels.append('0')

for i in range(3):
    checkbuttonChannels[i] = Checkbutton(root, text = str(i), variable = varChannels[i]).pack()

button = Button(root, text = "Show Histograms", command = show).pack()

root.mainloop()