I am new to Python and Tkinter but I was wondering if I could do Multithreading in Tkinter.
I have a Restaurant Simulation program and whenever it accepts an order, this is what should happen:
1) Timer that counts down and shows how many seconds are left before the order is done
2) While the Timer is counting, I want to create another instance of the Restaurant Simulation so that it could accept another order.
This is what I have tried:
from Tkinter import *
class food():
def __init__(self):
self.inventory = []
def cookOrder(self,type):
if type is 'AA': #Cook Barf
self.inventory[0]+=1
class Restaurant():
def Callback(self,root):
if tkMessageBox.askokcancel("Quit", "Do you really wish to quit?"):
root.destroy()
def MainMenu(self):
self.Main = Tk()
self.Main.grid()
Title = Label(self.Main,text = "Welcome to Resto!",font=("Bauhaus 93",20))
Title.grid(columnspan=6)
RestoMenu = Button(self.Main,text = "Order Food",command = lambda:self.Restaurant_Menu('AA'),font=("High Tower Text",12))
RestoMenu.grid(row=2,column=0)
self.Main.mainloop()
def Restaurant_Menu(self,type):
self.Main.destroy()
self.setCookTime(type)
def setCookTime(self,type):
self.MainMenu() #This is not working as I planned it to be
self.cookTimer = Tk()
self.timeLabel = Label(text="")
self.timeLabel.pack()
if type is "AA":
self.Tick(10,type)
self.cookTimer.mainloop()
self.cookTimer.wm_protocol ("WM_DELETE_WINDOW", self.Callback(self.cookTimer)) #Getting TCL Error
def Tick(self,time,type):
time -=1
if time ==-1:
food.cookOrder(type)
self.cook.destroy()
else:
self.timeLabel.configure(text="%d" %time)
self.cookTimer.after(1000, lambda: self.Tick(time,type))
Food = food()
Resto = Restaurant()
Resto.MainMenu()
Now, the problem with the code is, it is not creating another instance of the Restaurant while the countdown is going on. Any help?
Plus, how do you ask the user for the confirmation of exiting program when he clicks the exit button while the timer is ticking, using WM_DELETE_WINDOW?
Related
1) What is my goal:
I’m creating an application that should read data every 60s from ModBusServer, append those data to Graphs and then when the app is closed save the data to excel file.
Site note:
The process of reading data from ModBusServer and appending them to graphs should start after a start button is pressed.
And end after stop button is pressed OR when ModBusServer sends a request to stop.
2) What I have so far:
I created the GUI without any major problems as a class “GUI_komora”.
Everything there works just fine.
3) What is the problem:
But now I’m lost on how to approach the “read data every 60 seconds”, and overall how to control the application.
I did some research on threading but still I’m confused how to implement this to my application.
I learned how to make functions run simultaneously in this tutorial.
And also how to call a function every few seconds using this question.
But none of them helped me to learn how to control the overall flow of the application.
If you could redirect me somewhere or tell me about a better approach I would be really glad.
Some of my code:
from tkinter import *
from GUI_komora import GUI
root = Tk()
my_gui = GUI(root) #my GUI class instance
#main loop
root.mainloop()
"""
How do I achieve something like this???
whenToEnd = False
while whenToEnd:
if step == "Inicialzation":
#inicializace the app
if step == "ReadData":
#read data every 60 seconds and append them to graphs
if step == "EndApp"
#save data to excel file and exit app
whenToEnd = True
"""
Here is an example of a loop that takes a decision (every 60 sec in your case) and pushes the outcome of the decision to tkinter GUI: https://github.com/shorisrip/PixelescoPy/blob/master/base.py
Parts:
main thread - starts tkinter window
control thread - reads some data and decides what to show in GUI
GUI class - has a method "add_image" which takes input an image and displays on GUI.(add_data_to_graph maybe in your case). This method is called everytime by the control thread.
Snippets:
def worker(guiObj, thread_dict):
# read some data and make decision here
time.sleep(60)
data_to_show = <outcome of the decision>
while some_logic:
pictureObj = Picture(chosen, timer)
pictureObj.set_control_thread_obj(thread_dict["control_thread"])
guiObj.set_picture_obj(pictureObj)
pictureObj.display(guiObj)
# do post display tasks
guiObj.quit_window()
# Keep GUI on main thread and everything else on thread
guiObj = GuiWindow()
thread_list = []
thread_dict = {}
thread_for_image_control = threading.Thread(target=worker, args=(guiObj,
thread_dict))
thread_dict["control_thread"] = thread_for_image_control
thread_list.append(thread_for_image_control)
thread_for_image_control.start()
guiObj.run_window_on_loop()
# thread_for_image_control.join()
Code for Picture class:
class Picture:
def __init__(self, path, timer):
self.path = path
self.timer = timer
self.control_thread_obj = None
def set_control_thread_obj(self, thread_obj):
self.control_thread_obj = thread_obj
def display(self, guiObj):
image_path = self.path
guiObj.add_image(image_path)
time.sleep(self.timer)
Code for GUI class
class GuiWindow():
def __init__(self):
self.picture_obj = None
self.root = Tk()
self.image_label = None
self.image = None
self.folder_path = None
self.timer = None
self.root.protocol("WM_DELETE_WINDOW", self.exit_button)
def add_image(self, image_path):
resized_img = self.resize(image_path)
image_obj = ImageTk.PhotoImage(resized_img)
image_label = Label(self.root, image=image_obj,
height=resized_img.height,
width=resized_img.width)
self.image = image_obj # DO NOT REMOVE - Garbage collector error
if self.image_label is not None:
self.remove_image()
image_label.grid(row=0, column=0, columnspan=3)
self.image_label = image_label
Here based on my control loop thread I am changing image (in your case graph data) of the tkinter GUI.
Does this help?
I like to create an object per second and make the show up one by one. However, the code below wait for 3 seconds and show them all at the same time.
from tkinter import *
import time
def create():
for i in range(3):
r4=Radiobutton(root, text="Option 1"+str(i), value=1)
r4.pack( anchor = W )
time.sleep(1)
root = Tk()
create()
root.mainloop()
Your code, as is, creates a one object per second as you desired it, but this objects need to be shown, and they're shown when code flow reaches the mainloop. Hence, for observer, it looks like there're no objects at all after one second.
Of course, you can use sleep and update, but beware - sleeping leads to unresponsive window, so it's OK option (to be honest - not OK at all), if your application isn't drawn and you're outside of mainloop, but if it's not - prepare for a "frozen" window, because GUI can redraw himself only in mainloop (an event loop, you can reach it with update as well) and sleep blocks this behaviour.
But there's a good alternative, the after method, take a look on it!
And there's a snippet, so you can see the difference:
try:
import tkinter as tk
except ImportError:
import Tkinter as tk
import time
def create_with_sleep():
for _ in range(3):
tk.Radiobutton(frame_for_sleep, text="Sleep Option").pack(anchor='w')
time.sleep(int(time_entry.get()))
root.update()
def create_with_after(times=3):
if times != 0:
tk.Radiobutton(frame_for_after, text="After Option").pack(anchor='w')
times -= 1
root.after(int(time_entry.get()) * 1000, lambda: create_with_after(times))
root = tk.Tk()
test_yard_frame = tk.Frame(root)
frame_for_sleep = tk.Frame(test_yard_frame)
frame_for_after = tk.Frame(test_yard_frame)
test_yard_frame.pack()
frame_for_sleep.pack(side='left')
frame_for_after.pack(side='left')
button_frame = tk.Frame(root)
button_for_sleep = tk.Button(button_frame, text='Create 3 radiobuttons with sleep+update', command=create_with_sleep)
button_for_after = tk.Button(button_frame, text='Create 3 radiobuttons with after', command=create_with_after)
button_frame.pack()
button_for_sleep.pack(side='left')
button_for_after.pack(side='left')
time_label = tk.Label(root, text='Time delay in seconds:')
time_label.pack(fill='x')
time_entry = tk.Entry(root)
time_entry.insert(0, 1)
time_entry.pack(fill='x')
root.mainloop()
With 1 seconds delay there's no much difference, but you can try to increase delay to understand why after option is preferable in general.
You can use update to call a refresh on your objects.
In use, you would have to add the line root.update() in your for loop.
I'm designing a GUI application that converts between celsius and fahrenheit. For now, there're primarily two problems that I'm not able to tackle:
1) When I enter an integer that needs to be converted based on the given conversion formula, the Label from tkinter cannot display the output properly. In fact, it shows something like this:
<conversionModel.Conversion object at 0x1057b11d0>
which made it really difficult for debug to a beginner like me.
2) There's a quitButton, thought which we can destroy() the GUI application. The problem is that when I close the GUI by clicking the red cross of the window, the Shell says:
_tkinter.TclError: can't invoke "destroy" command: application has been destroyed
I checked answers to other questions regarding the same problem, it turned out that it was because this GUI application was destroyed before closing. I had no idea how to address this particular problem.
Below are three pieces of code written in Model/View/Controller form:
The Model in conversionModel.py:
class Conversion:
"""
class Conversion is the Model for a celsius-fahrenheit conversion
application. It converts celsius into fahrenheit and fahrenheit into
celsius.
"""
def toCelsius(self, temp):
return (5 / 9) * (temp - 32)
def toFahrenheit(self, temp):
return ((9 / 5) * temp) + 32
The View in conversionView.py:
import tkinter
class MyFrame(tkinter.Frame):
def __init__(self, controller):
tkinter.Frame.__init__(self)
self.pack()
self.controller = controller
self.tempEntry = tkinter.Entry()
self.tempEntry.insert(0, "0")
self.tempEntry.pack({"side": "left"})
self.celsiusButton = tkinter.Button(self)
self.celsiusButton["text"] = "Celsius"
self.celsiusButton["command"] = self.controller.buttonToC
self.celsiusButton.pack({"side": "left"})
self.fahrenheitButton = tkinter.Button(self)
self.fahrenheitButton["text"] = "Fahrenheit"
self.fahrenheitButton["command"] = self.controller.buttonToF
self.fahrenheitButton.pack({"side": "left"})
self.labelForOutput = tkinter.Label(self)
self.labelForOutput["text"] = 0
self.labelForOutput.pack ({"side": "left"})
self.quitButton = tkinter.Button(self)
self.quitButton["text"] = "Quit"
self.quitButton["command"] = self.quit
self.quitButton.pack({"side": "left"})
The Controller in controller.py:
import tkinter
import conversionView
import conversionModel
class Controller:
def __init__(self):
root = tkinter.Tk()
self.model = conversionModel.Conversion()
self.view = conversionView.MyFrame(self)
self.value = float(self.view.tempEntry.get())
self.view.mainloop()
root.destroy()
def buttonToC(self):
self.model.toCelsius(self.value)
self.view.labelForOutput["text"] = str(self.model) + " °C"
def buttonToF(self):
self.model.toFahrenheit(self.value)
self.view.labelForOutput["text"] = str(self.model) + " °F"
if __name__ == "__main__":
c = Controller()
For #1, you need to read the tempEntry control each time you do a conversion, and capture the result of the conversion for printing. As it is now you only read the tempEntry control on __init__, and str(self.model) just prints out the name of the model object. This should work:
def buttonToC(self):
fahr = float(self.view.tempEntry.get())
temp = self.model.toCelsius(fahr)
self.view.labelForOutput["text"] = str(temp) + " °C"
def buttonToF(self):
celsius = float(self.view.tempEntry.get())
temp = self.model.toFahrenheit(celsius)
self.view.labelForOutput["text"] = str(temp) + " °F"
For #2, I'm not familiar enough with Tk yet to know why the Quit button works correctly but the red X destroys the windows before you get around to calling root.destroy, but this should work around it:
self.view.mainloop()
try:
root.destroy()
except tkinter.TclError:
pass
The Quit button needs the destroy, but the X button doesn't and throws an exception. This code just ignores the exception in the X button case.
i'm trying to manage two MainWindow (MainWindow & AccessWindow) with PyQt for my RFID ACCESS CONTROL Project.
I want to show the first MainWindow all time (Endless Loop).
Then, i want to hide it and show the second MainWindow when the RFID Reader (who's working on "auto-reading mode") read an RFID Tag.
so in the main python program i have a pseudo "do while" loop (while True: and break with a condition) to read on serial port the data provided by the reader. Then i check a DB.. It's not important. So the trigger event is "when the reader read something).
I got some help from another forum and now i have this:
# -*- coding: utf-8 -*-
from PyQt4 import QtCore, QtGui
import sys, pyodbc, serial
import os
import time
#Variables
Code_Zone = "d"
class MainWindow(QtGui.QWidget):
def __init__(self, main):
super(MainWindow, self).__init__()
self.main = main
self.grid = QtGui.QGridLayout(self)
self.welcome = QtGui.QLabel("WELCOME", self)
self.grid.addWidget(self.welcome, 2, 2, 1, 5)
class AccessWindow(QtGui.QWidget):
def __init__(self):
super(AccessWindow, self).__init__()
self.setMinimumSize(150, 50)
self.grid = QtGui.QGridLayout(self)
self.label = QtGui.QLabel(self)
self.grid.addWidget(self.label, 1, 1, 1, 1)
class Main(object):
def __init__(self):
self.accueil = MainWindow(self)
self.accueil.show()
self.access = AccessWindow()
def wait(self):
# RFID READER ENDLESS LOOP
while 1:
global EPC_Code
ser = serial.Serial(port='COM6', baudrate=115200)
a = ser.read(19).encode('hex')
if (len(a)==38):
EPC_Code = a[14:]
print ('EPC is : ' + EPC_Code)
break
else:
continue
ser.close()
self.on_event(EPC_Code)
def on_event(self, data):
def refresh():
self.toggle_widget(False)
self.wait()
# vérification des données
EPC_Code = data
sql_command = "[Get_Access_RFID] #Code_RFID = '"+EPC_Code+"', #Code_Zone = '"+Code_Zone+"'" # STORED PROCEDURE
db_cursor.execute(sql_command)
rows = db_cursor.fetchone()
result= str(rows[0])
print ("result = " + str(result))
if result == "True":
# si OK
self.access.label.setText('ACCESS GRANTED')
else:
# si pas OK
self.access.label.setText('ACCESS DENIED')
self.toggle_widget(True)
QtCore.QTimer.singleShot(2000, refresh)
def toggle_widget(self, b):
self.accueil.setVisible(not b)
self.access.setVisible(b)
if __name__=='__main__':
cnxn = """DRIVER={SQL Server};SERVER=***;PORT=***;UID=***;PWD=***;DATABASE=***"""
db_connection = pyodbc.connect(cnxn)
db_cursor = db_connection.cursor()
print ('Connected TO DB & READY')
app = QtGui.QApplication(sys.argv)
main = Main()
main.wait()
sys.exit(app.exec_())
and now my problem is that the text of the first window doesn't appear when i run the program but the text of the second window appear when i keep my badge near the RFID Reader.
Instead of two MainWindow, create one. As content, create two classes which extend QtGui.QWidget called MainView and AccessView. Instead of replacing the window, just put the correct view into the window. That way, you can swap views without opening/closing windows.
If you use a layout, then the window will resize to fit the view.
The next problem is that you block the UI thread which means Qt can't handle events (like the "paint UI" event). To fix this, you must move the RFID handling code in a background thread. You can emit signals from this background thread to update the UI.
Note: You must not call UI code from a thread!! Just emit signals. PyQt's main loop will see them and process them.
Related:
https://joplaete.wordpress.com/2010/07/21/threading-with-pyqt4/
Updating GUI elements in MultiThreaded PyQT, especially the second example using signals. The first example is broken (calling addItem() from a thread) is not allowed)
I've just been trying to practice some code by making a simple dice game
and using tkinter for the user interface of the starting menu for the game
For the starting menu, I'm trying to just see how it will come out if I used the code below,
BUT before making the Button widget and the Label Widgets, the commands come up first.
How would I fix this up?
thanks in advance
import tkinter as tk
from main import main
from written import showInstructions, showCredits
from generate_no import generate_no
class DiceGameUI(tk.Frame):
def __init__(self, master = None):
tk.Frame.__init__(self, master)
self.grid()
self.createWidgets()
def createWidgets(self):
self.titleLabel = tk.Label(self, fg = "red") #The Title of the Game
self.titleLabel["text"] = "Dice Game"
self.startButton = tk.Button(self) #Start Button
self.startButton["text"] = "Roll On!"
self.startButton["command"] = main() <<----- This plays out first before
self.startButton.grid() making any widgets
self.instrButton = tk.Button(self) #Instructions Button
self.instrButton["text"] = "Instructions"
self.instrButton["command"] = showInstructions()
self.instrButton.grid()
self.credits = tk.Button(self) #Credits Button
self.credits["text"] = "Credits"
self.credits["command"] = showCredits()
self.credits.grid()
root = tk.Tk() #Run code using tkinter
app = DiceGameUI(master = root)
app.mainloop()
'
You have to assign only name of function without () and arguments
self.startButton["command"] = main
If you use () than you run that function and result is assigned to command. It is good to create dynamicly function for command.
If you will need assign function which require arguments you have to use lambda function.
self.startButton["command"] = lambda:main()
self.startButton["command"] = lambda:main("abc", 123)
a = "abc"
b = 123
self.startButton["command"] = lambda arg1=a,arg2=b:main(arg1,arg2)
self.startButton["command"] = lambda title=a,count=b:main(title,count)
# this may not work - especially if a or b changes value (for example in loop)
self.startButton["command"] = lambda:main(a, b)
example how to use function name in own code
def plus(a, b):
return a + b
def minus(a, b):
return a - b
def result(a, b, func_name):
return func_name(a,b)
print result(10, 7, plus) # 17
print result(10, 7, minus) # 3