Print the difference result between two counters in Python - python-3.x

Question

I have two counters whose results are displayed in a small part of the GUI for reference, but the important data I need is the result of IN minus OUT. For example, if I have 113 IN and 86 OUT, I am going to display those two data but I need to display also the result, 27 (113-86=27).
Screenshot of the app
Given these two counters:
def counter_label_IN(label):
def count():
s.sendall(b'gcounters\x00')
L_IN = next(iter(s.recv(1024)))
print(L_IN)
label_IN.config(text=str(L_IN))
label_IN.after(500, count)
count()
def counter_label_OUT(label):
def count():
s.sendall(b'gcounters\x00')
L_OUT = next(iter(s.recv(1024)))
print(L_OUT)
label_OUT.config(text=str(L_OUT))
label_OUT.after(500, count)
count()
How can I have another timer keeping refreshing the difference between the two?
Also, if the difference is a negative number, I need to display only 0.
EDIT after #j_4321 kind reply.
Thank you so much for the reply. I am a little lost and I guess it is one of those time the reply is right in front of my eyes but it is so bright that I can't see it... The code written gives no error, but the counts displayed in all the labels are zeroes. This is a simplified code, but still you can see the 0:
EDIT 2 after #j_4321 kind reply.
As suggested, I added:
counter_label_IN()
counter_label_OUT()
To the code, which I am pasting here for your consideration. It now gives me this error:
PS C:\Users\lorenzo.amati> & C:/Users/lorenzo.amati/AppData/Local/Programs/Python/Python38-32/python.exe "c:/Users/lorenzo.amati/Desktop/Software PCN/PCN-local-getdata-prova.py"
Traceback (most recent call last):
File "c:/Users/lorenzo.amati/Desktop/Software PCN/PCN-local-getdata-prova.py", line 55, in <module>
counter_label_IN()
File "c:/Users/lorenzo.amati/Desktop/Software PCN/PCN-local-getdata-prova.py", line 38, in counter_label_IN
count()
File "c:/Users/lorenzo.amati/Desktop/Software PCN/PCN-local-getdata-prova.py", line 27, in count
s.sendall(b'gcounters\x00')
OSError: [WinError 10038] An operation was attempted on something that is not a socket
Here is the code:
import socket
import tkinter as tk
import tkinter.ttk as ttk
# Main settings
IP_address = ('172.16.0.103')
root = tk.Tk()
root.title("People Counter")
root.configure(bg="#006bb3")
font1 = "-family {Source sans pro} -size 36 -weight bold"
font2 = "-family {Source sans pro} -size 150 -weight bold"
# use IntVar as counters
counter_IN = tk.IntVar(root)
counter_OUT = tk.IntVar(root)
counter_DIFF = tk.IntVar(root)
# get the sensor data
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((IP_address,5400))
def counter_label_IN():
def count():
s.sendall(b'gcounters\x00')
L_IN = next(iter(s.recv(1024)))
print(L_IN)
counter_IN.set(L_IN) # update counter IntVar instead of label
# update DIFF counter:
diff = L_IN - counter_OUT.get()
if diff < 0:
diff = 0
counter_DIFF.set(diff)
label_IN.after(500, count)
count()
def counter_label_OUT():
def count():
s.sendall(b'gcounters\x00')
L_OUT = next(iter(s.recv(1024)))
print(L_OUT)
counter_OUT.set(L_OUT) # update counter IntVar instead of label
diff = counter_IN.get() - L_OUT
if diff < 0:
diff = 0
counter_DIFF.set(diff)
label_OUT.after(500, count)
count()
s.close()
counter_label_IN()
counter_label_OUT()
# In/Out Informations display on top
FrameTOP = tk.Frame(root, bg="#006bb3", borderwidth="0")
FrameTOP.grid(row=0, column=0, columnspan=4, sticky='nsew')
Label_RTC_IN = tk.Label(FrameTOP, anchor='w',bg="#006bb3", fg='white',justify='left', text='Realtime count of people IN:')
Label_RTC_OUT = tk.Label(FrameTOP, anchor='w',bg="#006bb3", fg='white',justify='left', text='Realtime count of people OUT:')
label_IN = tk.Label(FrameTOP, textvariable=counter_IN, anchor='w',bg="white",fg="black", justify='left', relief='sunken', borderwidth="2")
label_OUT = tk.Label(FrameTOP, textvariable=counter_OUT, anchor='w',bg='white', fg='black', justify='left', relief='sunken', borderwidth="2")
Label_RTC_IN.grid(row=0, column=0, padx=10, pady=10)
label_IN.grid(row=0, column=1, padx=10, pady=10)
Label_RTC_OUT.grid(row=0, column=2, padx=10, pady=10)
label_OUT.grid(row=0, column=3, padx=10, pady=10)
# Frame in which to put the differential data of people inside
FrameCENTRAL = tk.Frame(root, bg="#006bb3",borderwidth="0")
FrameCENTRAL.grid(row=1, column=0, pady=50, columnspan=4,) #sticky='nsew')
TitleCentral = tk.Label(FrameCENTRAL,anchor='w', bg="#006bb3", fg='white', font=font1, text='''People Inside''')
TitleCentral.grid(row=0, column=0, padx=10, pady=10)
label_DIFF = tk.Label(FrameCENTRAL, textvariable=counter_DIFF, font=font2, bg="#006bb3", fg='white', anchor='center')
label_DIFF.grid(row=1, column=0, padx=10, pady=10)
# IP Informations
FrameBOTTOM = tk.Frame(root, bg="#006bb3", borderwidth="0")
FrameBOTTOM.grid(row=2, column=0, columnspan=4, sticky='nsew')
Label_IP_ADDRESS = tk.Label(FrameBOTTOM,anchor='w',bg="#006bb3",fg='white',text='''People counter sensor locally connected to local IP address:''')
Label_IP = tk.Label(FrameBOTTOM,anchor='w',bg="#006bb3",fg='white',text=(IP_address))
Label_IP_ADDRESS.grid(row=0, column=0, padx=10, pady=10)
Label_IP.grid(row=0, column=1, padx=10, pady=10)
# Closing button
close = tk.Button(FrameBOTTOM, bg="#006bb3",fg='white',text='Stop and close', width=16, command=root.destroy)
close.grid(row=0, column=3, padx=10, sticky='e')
root.mainloop()
Screenshot of the app after the modification, showing all 0

Answer 1

You can use IntVar as the IN, OUT and DIFF = IN - OUT counters and use the textvariable option of the Label to automatically update the text when updating the counters. In the counter_label_...() functions, the IntVar value will be updated instead of updating the label's text.
import tkinter as tk
root = tk.Tk()
# use IntVar as counters
counter_IN = tk.IntVar(root)
counter_OUT = tk.IntVar(root)
counter_DIFF = tk.IntVar(root)
# use textvariable to keep the labels updated
label_IN = tk.Label(root, textvariable=counter_IN)
label_OUT = tk.Label(root, textvariable=counter_OUT)
label_DIFF = tk.Label(root, textvariable=counter_DIFF)
# database polling
def counter_label_IN():
def count():
s.sendall(b'gcounters\x00')
L_IN = next(iter(s.recv(1024)))
print(L_IN)
counter_IN.set(L_IN) # update counter IntVar instead of label
# update DIFF counter:
diff = L_IN - counter_OUT.get()
if diff < 0:
diff = 0
counter_DIFF.set(diff)
label_IN.after(500, count)
count()
def counter_label_OUT():
def count():
s.sendall(b'gcounters\x00')
L_OUT = next(iter(s.recv(1024)))
print(L_OUT)
counter_OUT.set(L_OUT) # update counter IntVar instead of label
diff = counter_IN.get() - L_OUT
if diff < 0:
diff = 0
counter_DIFF.set(diff)
label_OUT.after(500, count)
count()
# start monitoring the database
counter_label_IN()
counter_label_OUT()