python - checkbox in new window update fails and stays false - user-interface

Question

import matplotlib
from tkinter import *
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
import tkinter as tk
from tkinter import ttk
import numpy as np
import matplotlib.animation as animation
from matplotlib import style
from matplotlib import pyplot as plt
from scipy.misc import *
import webbrowser
import subprocess
import csv
import matplotlib.ticker as mticker
import matplotlib.dates as mdates
from os import startfile
LARGE_FONT = ("Times", 11, "bold italic")
NORM_FONT = ("Helvetica", 9)
SMALL_FONT = ("Helvetica",7)
HELP_FONT=("Times", 9 , "bold")
class PAL3_guide(tk.Tk):
def __init__(self,*args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.pack(side="top", fill="both", expand = True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (StartPage,Tut01):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(StartPage)
def show_frame(self, cont):
frame=self.frames[cont]
frame.tkraise()
class StartPage(tk.Frame):
def __init__(self,parent, controller):
tk.Frame.__init__(self,parent, background="white")
button_PAL = ttk.Button(self, text="Setup Guide", command=lambda:controller.show_frame(Tut01))
button_PAL.pack()
class Tut01(tk.Frame):
def __init__(self,parent,controller):
tk.Frame.__init__(self,parent)
var=BooleanVar()
label = tk.Label(self, text="Guide", font=LARGE_FONT)
label.pack(pady=10, padx=10)
label = tk.Label(self, text="Check the methods to accomplish", font=NORM_FONT)
label.pack(pady=10, padx=10)
c1 = Checkbutton(self, state=ACTIVE).pack()
c1Label = tk.Label(self, text="digestion1",font=SMALL_FONT).pack()
c2 = Checkbutton(self, state=ACTIVE).pack()
c2Label = tk.Label(self, text="digestion2",font=SMALL_FONT).pack()
c3 = Checkbutton(self, text="enrichment",state=ACTIVE, variable=var, command=lambda:onClick()).pack()
def onClick():
var.get()
if var == True:
print("hi")
else:
print("hiww")
app = PAL3_guide()
app.geometry("1280x920")
app.mainloop()
Please check last code lines around the c3 checkbox.
I dont get why my boolean variable var is not getting updated by clicking the checkbox on the 2nd page. By clicking the checkbox (c3) the GUI should act differently. However as mentioned above it is not getting updated.. and stays False. I feel it keeps the value from start and does not get changed. Thanks for help ..
EDIT:
Above the if statement missed the var.get() and I could make it work in smaller setup.. however, in the real tool I am calling a plt.figure() in the beginning since it included and anmiate function, If I erase this call, everything works like it should, might be that this figure calling forces the checkbutton to have the first onvalue ?

Answer 1

I would change var, to be self.var and set the off and on values explicitly:
offvalue=
The value corresponding to a non-checked button. The default is 0. (offValue/Value)
onvalue=
The value corresponding to a checked button. The default is 1. (onValue/Value)
c3 = Checkbutton(self, text="enrichment",state=ACTIVE,
variable=self.var, command=onClick,
onvalue=True, offvalue=False)
c3.pack()
command= does not take a function call, just a function.
You would have to write either
command=lambda: print(self.var.get())
OR:
def printVar():
print(self.var.get())
THEN:
..., command=printVar, ...
NOTICE the abscence of the paranthesis!
You are supposed to be settting command to a function.
When you use parenthesis, you CALL the function, you DO NOT want that here.