56 KiB
tkinter
Tkinter helloworld
The absolute most basic way to have a hello world GUI program up and running with Tkinter is the following.
from tkinter import *
root = Tk()
MyLabel = Label(root,text="hello world")
MyLabel.pack()
root.mainloop()
Tkinter have two popular architectures, the Tcl and Tk. This two architectures are different, they have their own functionality and their own official documentation. We are gonna use the Tk architecture.
The Tk architecture is used to create a GUI widget. He adds a lot of custom commands, so the widget is very customizable.
In the previous code,the mainloop()
instruction allows us to open the main window and to not close immediately the window.
And then, the Label()
method creates label in a layout. This method has many parameters to customize a label. The instruction pack()
will be always call , this instruction can
add and adjust a widget.
While it works we know better by now.
We should include the if __name__ == "__main__"
statement.
from tkinter import *
if __name__ == "__main__":
root = Tk()
MyLabel = Label(root,text="hello world")
MyLabel.pack()
root.mainloop()
The instance of Tk()
is what will actually process our event loop and the root
is the content of our window. We can customize root
with instruction like geometry, title,etc.
In the latter we will create our button and labels so should create our own class and inherit from it.
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Label.__init__(self, text="hello world")
self.pack()
if __name__ == "__main__":
root = Tk()
root.title("title of the window")
root.geometry("500x300")
MainWindow()
root.mainloop()
We can add content to the frame, such as labels, input boxes and buttons as follows.
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Label.__init__(self, text="hello world")
#Label
MyLabel = Label(self, text="This is a label")
MyLabel.pack()
self.config(bg="yellow")
self.pack()
if __name__ == "__main__":
root = Tk()
root.title("title of the window")
root.geometry("500x300")
MainWindow()
root.mainloop()
Let's try to put multiple visual object into the same frame.
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Label.__init__(self, text="hello world")
#Label
MyLabel = Label(self, text="This is a label")
MyLabel.pack()
#Button
MyButton = Button(self, text="I'm clickable!")
MyButton.pack()
self.config(bg="yellow")
self.pack()
if __name__ == "__main__":
root = Tk()
root.title("title of the window")
root.geometry("500x300")
MainWindow()
root.mainloop()
You see how they are stacked one on top of the other? We can overcome this problem with parameters of pack(). We can also use other geometry managers like grid() and place().
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self, master=None)
MyPanel = PanedWindow.__init__(self, bg="Blue")
#Label
MyLabel = Label(MyPanel, text="this is a label", bg= "yellow")
MyLabel.pack(fill="x")
#Bouton
MyButton = Button(MyPanel, text="I'm clickable!")
MyButton.place(x=10, y=50)
self.pack(fill=BOTH,expand=True)
if __name__ == "__main__":
root = Tk()
root.title("this is the title of the window")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
This is looking better!
But it requires some explanation though.
Let's break it down.
The Frame.__init__
is your window in which you create a PanedWindow.__init__
which is used to draw thing to.
To this panel you're adding two different objects (Label()
and Button()
) each with or without their own settings (such as a label or not).
It probably looks a bit convoluted but this is how most GUI libraries work internally.
- You create a frame
- Within this frame you create a drawing area and set some form of automatic layout to it.
- You create the visual elements you want and add them one by one to the drawing area.
- Success
Now how do we link user input to code actions?
This is a complicated way of saying actually do something when I click the damn button!
For this we'll need to create a function, or better yet a method to the Frame.__init__
objects.
Each time we click the button, that method will be called.
Because it is a method it has access to self so it can modify anything within the scope of the instance.
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self, master=None)
MyPanel = PanedWindow.__init__(self, bg="Blue")
#Label
MyLabel = Label(MyPanel, text="this is a label", bg= "yellow")
MyLabel.pack(fill="x")
#Bouton
MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyLabel))
MyButton.place(x=10, y=50)
self.pack(fill=BOTH,expand=True)
def ButtonEnable(self, Label):
global number
number += 1
counter = "You have press the button {} time".format(number)
Label.config(text=counter)
number=0
if __name__ == "__main__":
root = Tk()
root.title("this is the title of the window")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
We can use the same idea to grab input from the textbox.
from tkinter import *
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self, master=None)
MyPanel = PanedWindow.__init__(self, bg="Blue")
#Label
MyLabel = Label(MyPanel, text="this is a label", bg= "yellow")
MyLabel.pack(fill="x")
#TextBox
MyEntry = Entry(MyPanel)
MyEntry.place(x=200,y=50)
#Bouton
MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyLabel,MyEntry))
MyButton.place(x=10, y=50)
self.pack(fill=BOTH,expand=True)
def ButtonEnable(self, MyLabel, MyEntry):
MyText = MyEntry.get()
MyLabel.config(text=MyText)
if __name__ == "__main__":
root = Tk()
root.title("this is the title of the window")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
Tkinter guess the number
import time
from tkinter import *
import random
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self, master=None, bg="white")
MyPanel = PanedWindow.__init__(self)
MyNumber = random.randint(0, 100)
#Label
self.MyLabel = Label(MyPanel, text="I have a number in mind...", bg= "blue")
self.MyLabel.pack(fill="x", ipadx=25, ipady=20)
#TextBox
MyEntry = Entry(MyPanel)
MyEntry.place(x=200,y=90)
#Bouton
MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyEntry, MyNumber))
MyButton.place(x=10, y=90)
self.pack(fill=BOTH,expand=True)
def ButtonEnable(self, MyEntry, MyNumber):
if self.IsCorrect(MyEntry.get()):
number = int(MyEntry.get())
if number != MyNumber:
self.GameOver(number, MyNumber)
else:
self.Win()
else:
self.MyLabel.config(text="I need numbers!")
def GameOver(self, number, MyNumber):
if number > MyNumber:
self.MyLabel.config(text="My number is smaller")
else:
self.MyLabel.config(text="My number is bigger")
def Win(self):
self.MyLabel.config(text="You WIN!")
def IsCorrect(self, MyEntry):
x = str(MyEntry)
if x.isdigit() == True:
return True
else:
return False
if __name__ == "__main__":
root = Tk()
root.title("Guess the number")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
MVC design pattern
A simple console only MVC. We'll add the GUI view in a bit.
from tkinter import *
class ConsoleView(object):
"""A view for console."""
def select_task(self):
"""Asks which index to look up."""
idx = input("which task do you want to see? ")
return idx
def show(self, task):
"""Displays the task to the console. This method is called from the
controller."""
print("your task: {}".format(task))
def error(self, msg):
"""Prints error messages coming from the controller."""
print("error: {}".format(msg))
class Model(object):
"""The model houses add data and should implement all methods related to
adding, modifying and deleting tasks."""
db = ["go to the shops", "dryhop beer", "drop of motorbike"]
def get_task(self, idx):
"""Performs a task lookun into the database and returns it when found.
If no task is found, it returns an error message that will be displayed
in the view (via the controller)."""
try:
task = Model.db[idx]
except IndexError:
task = "task with {} not found!".format(idx)
return task
class Controller(object):
"""Binds the model and the view together."""
def __init__(self, view):
self.model = Model()
self.view = view
def run(self):
"""The controller's main function. Depending on what type of view is
selected, a different event loop is setup. Do note that the ConsoleView
is not a real event loop, just a basic flow of action."""
if self.view is ConsoleView:
self.view = self.view()
self._run_console_view()
elif self.view is TkinterView:
root = Tk()
root.title("Task Manager")
root.geometry("500x300")
self.view = self.view()
self.view._set_controller(self)
root.mainloop()
def get_task_from_model(self, idx):
"""Needed for the TkinterView to communicate with the controller."""
task = self.model.get_task(idx)
self.view.show_task(task)
def _run_console_view(self):
"""Super simple event loop."""
while True:
try:
idx = self.view.select_task()
idx = int(idx)
except Exception as e:
self.view.error(e)
continue
task = self.model.get_task(idx)
self.view.show(task)
if __name__ == "__main__":
view = ConsoleView
app = Controller(view)
app.run()
And now with the implemented TkinterView
class.
from tkinter import *
class ConsoleView(object):
"""A view for console."""
def select_task(self):
"""Asks which index to look up."""
idx = input("which task do you want to see? ")
return idx
def show(self, task):
"""Displays the task to the console. This method is called from the
controller."""
print("your task: {}".format(task))
def error(self, msg):
"""Prints error messages coming from the controller."""
print("error: {}".format(msg))
class TkinterView(Frame):
"""A view using a wx.Dialog window"""
def __init__(self):
Frame.__init__(self, master=None)
#Panel
self.panel = PanedWindow(self, bg="green")
self.panel.pack(fill=BOTH, expand=True)
#Task Label
self.task = Label(self.panel, text="your task")
self.task.pack(expand=True)
#SpinBox
self.idx = Spinbox(self.panel, from_=0, to=2, wrap=True )
self.idx.pack(side= TOP)
#Button
self.button = Button(self.panel, text="submit", command=lambda : self.select_task())
self.button.pack(ipadx=60, ipady=30)
self.pack(fill=BOTH, expand=True)
def _set_controller(self, controller):
"""Set the controller so the view can communicate it's requests to it
and update it's values too."""
self.controller = controller
def select_task(self):
"""Gets the index to look up in the model and submits the request to
the controller."""
idx = self.idx.get()
self.controller.get_task_from_model(idx)
def show_task(self, task):
"""Updates the visual label in the view with the task. This method is
called from the controller."""
self.task.config(text=task)
class Model(object):
"""The model houses add data and should implement all methods related to
adding, modifying and deleting tasks."""
db = ["go to the shops", "dryhop beer", "drop of motorbike"]
def get_task(self, idx):
"""Performs a task lookun into the database and returns it when found.
If no task is found, it returns an error message that will be displayed
in the view (via the controller)."""
try:
task = Model.db[int(idx)]
except IndexError:
task = "task with {} not found!".format(idx)
return task
class Controller(object):
"""Binds the model and the view together."""
def __init__(self, view):
self.model = Model()
self.view = view
def run(self):
"""The controller's main function. Depending on what type of view is
selected, a different event loop is setup. Do note that the ConsoleView
is not a real event loop, just a basic flow of action."""
if self.view is ConsoleView:
self.view = self.view()
self._run_console_view()
elif self.view is TkinterView:
root = Tk()
root.title("Task Manager")
root.geometry("500x300")
self.view = self.view()
self.view._set_controller(self)
root.mainloop()
def get_task_from_model(self, idx):
"""Needed for the TkinterView to communicate with the controller."""
task = self.model.get_task(idx)
self.view.show_task(task)
def _run_console_view(self):
"""Super simple event loop."""
while True:
try:
idx = self.view.select_task()
idx = int(idx)
except Exception as e:
self.view.error(e)
continue
task = self.model.get_task(idx)
self.view.show(task)
if __name__ == "__main__":
view = TkinterView
app = Controller(view)
app.run()
For a GUI only login generator an implementation without MVC could look a bit like this. Note that the actual calculation is done inside the window itself. This is not a good idea because we should separate responsibilities into classes!
from tkinter import *
from tkinter import ttk
import login_generator
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self)
self.full_window = PanedWindow(self,orient=VERTICAL)
self.full_window.pack(fill=BOTH,expand=True)
self.create_top_panel()
self.create_bottom_panel()
self.pack(fill=BOTH, expand=True)
def create_bottom_panel(self):
bottom_panel = PanedWindow(self.full_window, bg="green")
bottom_panel.pack(fill=BOTH, side=BOTTOM)
#List
self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6)
self.login_list.pack()
self.login_list.heading("username", text="Username")
self.login_list.heading("password", text="Password")
self.login_list.bind("<ButtonRelease-1>", lambda e: self.show_popup())
def create_top_panel(self):
top_panel = PanedWindow(self.full_window, bg="red")
self.login_amount = Text(top_panel, height=5, width=52)
self.login_amount.place(x=10,y=10)
self.complex = BooleanVar()
self.complex.set(False)
self.login_complex = Checkbutton(top_panel, text="complex",var=self.complex)
self.login_complex.place(x=10,y=100)
self.login_create = Button(top_panel, text="Create", command=lambda: self.add_login())
self.login_create.place(x=100,y=100)
top_panel.pack(expand=True, fill=BOTH)
def show_popup(self):
global root
menu = Menu()
menu.add_command(label="Copy selected items", command=lambda : self.copy_items())
root.config(menu=menu)
def copy_items(self):
global root
try:
Item = self.login_list.item(self.login_list.focus())
FunctionValue = Item.values()
Array = list(FunctionValue)
Login = Array[2]
self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0],Login[1]))
except:
Msg = Toplevel(root)
l1 = Label(Msg, text="You have to take something")
l1.pack(fill=BOTH, expand=True)
def add_login(self):
self.username = login_generator.generate_username()
self.password = login_generator.generate_password(12,self.complex.get())
self.login_list.insert('', END,values=[self.username, self.password])
if __name__ == "__main__":
root = Tk()
root.title("Login Generator")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
Now let's assume the generate username and password function take some calculation time.
We'll add in a fake time.sleep
to simulate.
from tkinter import *
from tkinter import ttk
import login_generator
import time
class MainWindow(Frame):
def __init__(self):
Frame.__init__(self)
self.full_window = PanedWindow(self,orient=VERTICAL)
self.full_window.pack(fill=BOTH,expand=True)
self.create_top_panel()
self.create_bottom_panel()
self.pack(fill=BOTH, expand=True)
def create_bottom_panel(self):
bottom_panel = PanedWindow(self.full_window, bg="green")
bottom_panel.pack(fill=BOTH, side=BOTTOM)
#List
self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6)
self.login_list.pack()
self.login_list.heading("username", text="Username")
self.login_list.heading("password", text="Password")
self.login_list.bind("<ButtonRelease-1>", lambda e: self.show_popup())
def create_top_panel(self):
top_panel = PanedWindow(self.full_window, bg="red")
self.login_amount = Text(top_panel, height=5, width=52)
self.login_amount.place(x=10,y=10)
self.complex = BooleanVar()
self.complex.set(False)
self.login_complex = Checkbutton(top_panel, text="complex",var=self.complex)
self.login_complex.place(x=10,y=100)
self.login_create = Button(top_panel, text="Create", command=lambda: self.add_login())
self.login_create.place(x=100,y=100)
top_panel.pack(expand=True, fill=BOTH)
def show_popup(self):
global root
menu = Menu()
menu.add_command(label="Copy selected items", command=lambda : self.copy_items())
root.config(menu=menu)
def copy_items(self):
global root
try:
Item = self.login_list.item(self.login_list.focus())
FunctionValue = Item.values()
Array = list(FunctionValue)
Login = Array[2]
self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0],Login[1]))
time.sleep(1)
except:
Msg = Toplevel(root)
l1 = Label(Msg, text="You have to take something")
l1.pack(fill=BOTH, expand=True)
def add_login(self):
self.username = login_generator.generate_username()
self.password = login_generator.generate_password(12,self.complex.get())
self.login_list.insert('', END,values=[self.username, self.password])
if __name__ == "__main__":
root = Tk()
root.title("Login Generator")
root.geometry("500x300")
win = MainWindow()
root.mainloop()
A clear separation of responsabilities can be acchieved via an MVC pattern and a login library.
The library code is quite straightforward and goes as follows.
It's basically the same code we did before but with added try except
blocks.
Can you tell me why I added those?
import random
import string
def load_file(filename):
"""
We load a file and make a list out of it. Note that the same function is
used for both files (both adjectives and subjects). Functions should be
made as generic as possible.
There IS a problem you can fix, some logins will have spaces in them. Try
to remove them in this function!
"""
words = []
with open(filename, "r") as fp:
lines = fp.readlines()
for line in lines:
words.append(line.strip()) # what does strip() do, what does append() do? remember CTRL+Q!
return words
def generate_username():
"""
We'll generate a random pair of adjectives and subjects from two wordlists.
You NEED to have both files in you python project for this to work! Note
the capitalize method call to make it all prettier...
"""
try:
adjectives = load_file("./adjectives.txt")
except:
adjectives = ["big", "funny", "normal", "red"]
try:
subjects = load_file("./subjects.txt")
except:
subjects = ["giraffe", "elephant", "cougar", "tiger"]
adjective = random.choice(adjectives)
subject = random.choice(subjects)
username = adjective.capitalize() + subject.capitalize()
return username
def generate_password(length=10, complictated=True):
"""
We generate a password with default settings. You can overide these by
changing the arguments in the function call.
"""
password = ""
if complictated:
chars = string.ascii_letters + string.digits + string.punctuation
else:
chars = string.ascii_letters
for i in range(0, length):
password += random.choice(chars)
return password
if __name__ == "__main__":
# let's do some testing!
username_test = generate_username()
print(username_test)
password_test = generate_password()
print(password_test)
And now the GUI code nicely split up in a model, controller and a view. The overhead is quite large but it makes the code a lot more scalable.
from tkinter import *
from tkinter import ttk
import login_generator
import time
import threading
import queue
class View(Frame):
def __init__(self, controller):
Frame.__init__(self)
self.controller = controller
self.full_window = PanedWindow(self, orient=VERTICAL)
self.full_window.pack(fill=BOTH, expand=True)
self.create_top_panel()
self.create_bottom_panel()
self.pack(fill=BOTH, expand=True)
def create_bottom_panel(self):
bottom_panel = PanedWindow(self.full_window, bg="green")
bottom_panel.pack(fill=BOTH, side=BOTTOM)
# List
self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6)
self.login_list.pack()
self.login_list.heading("username", text="Username")
self.login_list.heading("password", text="Password")
self.login_list.bind("<ButtonRelease-1>", lambda e: self.show_popup())
def create_top_panel(self):
top_panel = PanedWindow(self.full_window, bg="red")
self.login_amount = Text(top_panel, height=5, width=52)
self.login_amount.place(x=10, y=10)
self.complex = BooleanVar()
self.complex.set(False)
self.login_complex = Checkbutton(top_panel, text="complex", var=self.complex)
self.login_complex.place(x=10, y=100)
self.login_create = Button(top_panel, text="Create", command=lambda: self.submit_request())
self.login_create.place(x=100, y=100)
top_panel.pack(expand=True, fill=BOTH)
def show_popup(self):
global app
menu = Menu()
menu.add_command(label="Copy selected items", command=lambda : self.copy_items())
app.config(menu=menu)
def copy_items(self):
try:
Item = self.login_list.item(self.login_list.focus())
FunctionValue = Item.values()
Array = list(FunctionValue)
Login = Array[2]
self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0], Login[1]))
time.sleep(1)
except:
Msg = Toplevel(root)
l1 = Label(Msg, text="You have to take something")
l1.pack(fill=BOTH, expand=True)
def submit_request(self):
amount = self.login_amount.get("1.0", END)
complex_bool = self.complex.get()
try:
amount = int(amount)
except:
amount = 1
self.controller.get_new_logins(amount, complex_bool)
def update_logins(self, login):
username, password = login
self.login_list.insert('', END, values=[username, password])
class Controller(object):
def __init__(self):
global app
app.title("Login Generator")
app.geometry("450x300")
self.view = View(self)
self.model = Model(self)
def get_new_logins(self, amount, complex_bool):
self.model.generate_login(amount, complex_bool)
def set_new_logins(self, logins):
self.view.update_logins(logins)
class Model(threading.Thread):
def __init__(self, controller):
threading.Thread.__init__(self, target=self.main)
self.controller = controller
self.queue = queue.Queue()
self.start()
def main(self):
while True:
amount, complex_bool = self.queue.get()
username = login_generator.generate_username()
password = login_generator.generate_password(12, complex_bool)
logins = (username, password)
self.controller.set_new_logins(logins)
time.sleep(1)
def generate_login(self, amount, complex_bool):
for i in range(0, amount):
self.queue.put((amount, complex_bool))
if __name__ == "__main__":
app = Tk()
mvc = Controller()
app.mainloop()
If you want to add a scrollbar in the project.
from tkinter import *
from tkinter import ttk
import login_generator
import time
import threading
import queue
class View(Frame):
def __init__(self, controller):
Frame.__init__(self)
self.controller = controller
self.full_window = PanedWindow(self, orient=VERTICAL)
self.full_window.pack(fill=BOTH, expand=True)
self.create_top_panel()
self.create_bottom_panel()
self.pack(fill=BOTH, expand=True)
def create_bottom_panel(self):
bottom_panel = PanedWindow(self.full_window, bg="green")
bottom_panel.pack(fill=BOTH, side=BOTTOM)
##Scrollbar
self.Scrollbar = Scrollbar(bottom_panel )
self.Scrollbar.pack(side=RIGHT, fill= Y)
# List
self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6, yscrollcommand= self.Scrollbar.set)
self.login_list.pack()
self.login_list.heading("username", text="Username")
self.login_list.heading("password", text="Password")
self.login_list.bind("<ButtonRelease-1>", lambda e: self.show_popup())
self.Scrollbar.config(command= self.login_list.yview)
def create_top_panel(self):
top_panel = PanedWindow(self.full_window, bg="red")
self.login_amount = Text(top_panel, height=5, width=52)
self.login_amount.place(x=10, y=10)
self.complex = BooleanVar()
self.complex.set(False)
self.login_complex = Checkbutton(top_panel, text="complex", var=self.complex)
self.login_complex.place(x=10, y=100)
self.login_create = Button(top_panel, text="Create", command=lambda: self.submit_request())
self.login_create.place(x=100, y=100)
top_panel.pack(expand=True, fill=BOTH)
def show_popup(self):
global app
menu = Menu()
menu.add_command(label="Copy selected items", command=lambda : self.copy_items())
app.config(menu=menu)
def copy_items(self):
try:
Item = self.login_list.item(self.login_list.focus())
FunctionValue = Item.values()
Array = list(FunctionValue)
Login = Array[2]
self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0], Login[1]))
time.sleep(1)
except:
Msg = Toplevel(root)
l1 = Label(Msg, text="You have to take something")
l1.pack(fill=BOTH, expand=True)
def submit_request(self):
amount = self.login_amount.get("1.0", END)
complex_bool = self.complex.get()
try:
amount = int(amount)
except:
amount = 1
self.controller.get_new_logins(amount, complex_bool)
def update_logins(self, login):
username, password = login
self.login_list.insert('', END, values=[username, password])
class Controller(object):
def __init__(self):
global app
app.title("Login Generator")
app.geometry("450x300")
self.view = View(self)
self.model = Model(self)
def get_new_logins(self, amount, complex_bool):
self.model.generate_login(amount, complex_bool)
def set_new_logins(self, logins):
self.view.update_logins(logins)
class Model(threading.Thread):
def __init__(self, controller):
threading.Thread.__init__(self, target=self.main)
self.controller = controller
self.queue = queue.Queue()
self.start()
def main(self):
while True:
amount, complex_bool = self.queue.get()
username = login_generator.generate_username()
password = login_generator.generate_password(12, complex_bool)
logins = (username, password)
self.controller.set_new_logins(logins)
time.sleep(1)
def generate_login(self, amount, complex_bool):
for i in range(0, amount):
self.queue.put((amount, complex_bool))
if __name__ == "__main__":
app = Tk()
mvc = Controller()
app.mainloop()
Coding challenge - Login generator with GUI
Coding challenge - Trivial pursuit with GUI
WXpython
wxpython helloworld
The absolute most basic way to have a hello world GUI program up and running with wxpython is the following.
import wx
app = wx.App()
frame = wx.Frame(None, title="hello world")
frame.Show()
app.MainLoop()
While it works we know better by now.
We should include the if __name__ == "__main__"
statement.
import wx
if __name__ == "__main__":
app = wx.App()
frame = wx.Frame(None, title="hello world")
frame.Show()
app.MainLoop()
The instance of wx.App
is what will actually process our event loop and the wx.Frame
is the content of our window.
In the latter we will create our button and labels so should create our own class and inherit from it.
import wx
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.Show()
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
We can add content to the frame, such as labels, input boxes and buttons as follows.
Note the first argument to the wx.StaticText
creation.
This is where we put the label into.
It kind of works but we'll encounter a problem when we pack more visual objects into the same frame.
import wx
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.label = wx.StaticText(self, label="this is a label")
self.Show()
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
Let's try to put multiple visual object into the same frame.
import wx
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.label = wx.StaticText(self, label="this is a label")
self.input = wx.TextCtrl(self)
self.button = wx.Button(self)
self.Show()
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
You see how they are stacked one on top of the other? We can overcome this problem with sizers. There are multiple ones we can use but let's dive into a first one called a box sizer.
import wx
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.panel = wx.Panel(self)
self.box = wx.BoxSizer()
self.label = wx.StaticText(self.panel, label="this is a label")
self.input = wx.TextCtrl(self.panel)
self.button = wx.Button(self.panel, label="I'm clickable!")
self.box.Add(self.label)
self.box.Add(self.input)
self.box.Add(self.button)
self.panel.SetSizer(self.box)
self.Show()
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
This is looking better!
But it requires some explanation though.
Let's break it down.
The wx.Frame
is your window in which you create a wx.Panel
which is used to draw thing to.
To this panel you're adding three different objects (wx.StaticText
, wx.TextCtrl
and wx.Button
) each with or without their own settings (such as a label or not).
Next you add these three objects to the wx.BoxSizer
and you tell the panel to use this box as sizer.
It probably looks a bit convoluted but this is how most GUI libraries work internally.
- You create a frame
- Within this frame you create a drawing area and set some form of automatic layout to it (the
wx.BoxSizer
). - You create the visual elements you want and add them one by one to the drawing area.
- Success
Now how do we link user input to code actions?
This is a complicated way of saying actually do something when I click the damn button!
For this we'll need to create a function, or better yet a method to the wx.Frame
objects.
Each time we click the button, that method will be called.
Because it is a method it has access to self so it can modify anything within the scope of the instance.
import wx
import random
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.panel = wx.Panel(self)
self.box = wx.BoxSizer()
self.label = wx.StaticText(self.panel, label="this is a label")
self.input = wx.TextCtrl(self.panel)
self.button = wx.Button(self.panel, label="I'm clickable!")
self.button.Bind(wx.EVT_BUTTON, self.set_label_value)
self.box.Add(self.label)
self.box.Add(self.input)
self.box.Add(self.button)
self.panel.SetSizer(self.box)
self.Show()
def set_label_value(self, event):
number = random.randint(0, 100)
self.label.SetLabel("{}".format(number))
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
We can use the same idea to grab input from the textbox.
import wx
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="hello world")
self.panel = wx.Panel(self)
self.box = wx.BoxSizer()
self.label = wx.StaticText(self.panel, label="this is a label")
self.input = wx.TextCtrl(self.panel)
self.button = wx.Button(self.panel, label="I'm clickable!")
self.button.Bind(wx.EVT_BUTTON, self.set_label_value)
self.box.Add(self.label)
self.box.Add(self.input)
self.box.Add(self.button)
self.panel.SetSizer(self.box)
self.Show()
def set_label_value(self, event):
msg = self.input.GetValue()
self.label.SetLabel("{}".format(msg))
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
wxpython guess the number
import wx
import random
class MainWindow(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="Guess the number")
self.number = random.randint(0, 100)
self.panel = wx.Panel(self)
self.box = wx.BoxSizer(wx.VERTICAL)
self.label = wx.StaticText(self.panel, label="I have a number in mind...")
self.input = wx.TextCtrl(self.panel)
self.button = wx.Button(self.panel, label="I'm clickable!")
self.button.Bind(wx.EVT_BUTTON, self.set_label_value)
self.box.Add(self.label)
self.box.Add(self.input)
self.box.Add(self.button)
self.panel.SetSizer(self.box)
self.Show()
def set_label_value(self, event):
result = self.input.GetValue()
if result.isdigit():
status, context = self.evaluate_user_number(int(result))
self.label.SetLabel(context)
else:
self.label.SetLabel("I need numbers!")
def evaluate_user_number(self, number):
if number > self.number:
return False, "my number is smaller"
elif number < self.number:
return False, "my number is bigger"
elif number == self.number:
return True, "You win!"
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
MVC design pattern
A simple console only MVC. We'll add the GUI view in a bit.
import wx
class ConsoleView(object):
"""A view for console."""
def select_task(self):
"""Asks which index to look up."""
idx = input("which task do you want to see? ")
return idx
def show(self, task):
"""Displays the task to the console. This method is called from the
controller."""
print("your task: {}".format(task))
def error(self, msg):
"""Prints error messages coming from the controller."""
print("error: {}".format(msg))
class WxView(wx.Dialog):
pass
class Model(object):
"""The model houses add data and should implement all methods related to
adding, modifying and deleting tasks."""
db = ["go to the shops", "dryhop beer", "drop of motorbike"]
def get_task(self, idx):
"""Performs a task lookun into the database and returns it when found.
If no task is found, it returns an error message that will be displayed
in the view (via the controller)."""
try:
task = Model.db[idx]
except IndexError:
task = "task with {} not found!".format(idx)
return task
class Controller(object):
"""Binds the model and the view together."""
def __init__(self, view):
self.model = Model()
self.view = view
def run(self):
"""The controller's main function. Depending on what type of view is
selected, a different event loop is setup. Do note that the ConsoleView
is not a real event loop, just a basic flow of action."""
if self.view is ConsoleView:
self.view = self.view()
self._run_console_view()
elif self.view is WxView:
app = wx.App()
self.view = self.view()
self.view._set_controller(self)
app.MainLoop()
def get_task_from_model(self, idx):
"""Needed for the WxView to communicate with the controller."""
task = self.model.get_task(idx)
self.view.show_task(task)
def _run_console_view(self):
"""Super simple event loop."""
while True:
try:
idx = self.view.select_task()
idx = int(idx)
except Exception as e:
self.view.error(e)
continue
task = self.model.get_task(idx)
self.view.show(task)
if __name__ == "__main__":
view = ConsoleView
# view = WxView
app = Controller(view)
app.run()
And now with the implemented WxView
class.
import wx
class ConsoleView(object):
"""A view for console."""
def select_task(self):
"""Asks which index to look up."""
idx = input("which task do you want to see? ")
return idx
def show(self, task):
"""Displays the task to the console. This method is called from the
controller."""
print("your task: {}".format(task))
def error(self, msg):
"""Prints error messages coming from the controller."""
print("error: {}".format(msg))
class WxView(wx.Dialog):
"""A view using a wx.Dialog window"""
def __init__(self):
wx.Dialog.__init__(self, None, title="Task Manager")
self.panel = wx.Panel(self)
self.box = wx.BoxSizer(wx.VERTICAL)
self.task = wx.StaticText(self.panel, label="your task")
self.idx = wx.SpinCtrl(self.panel)
self.button = wx.Button(self.panel, label="submit")
self.button.Bind(wx.EVT_BUTTON, self.select_task)
self.box.Add(self.task, 0, wx.EXPAND, 1)
self.box.Add(self.idx, 0, wx.EXPAND, 1)
self.box.Add(self.button, 0, wx.EXPAND, 1)
self.panel.SetSizer(self.box)
self.Show()
def _set_controller(self, controller):
"""Set the controller so the view can communicate it's requests to it
and update it's values too."""
self.controller = controller
def select_task(self, event):
"""Gets the index to look up in the model and submits the request to
the controller."""
idx = self.idx.GetValue()
self.controller.get_task_from_model(idx)
def show_task(self, task):
"""Updates the visual label in the view with the task. This method is
called from the controller."""
self.task.SetLabel(task)
class Model(object):
"""The model houses add data and should implement all methods related to
adding, modifying and deleting tasks."""
db = ["go to the shops", "dryhop beer", "drop of motorbike"]
def get_task(self, idx):
"""Performs a task lookun into the database and returns it when found.
If no task is found, it returns an error message that will be displayed
in the view (via the controller)."""
try:
task = Model.db[idx]
except IndexError:
task = "task with {} not found!".format(idx)
return task
class Controller(object):
"""Binds the model and the view together."""
def __init__(self, view):
self.model = Model()
self.view = view
def run(self):
"""The controller's main function. Depending on what type of view is
selected, a different event loop is setup. Do note that the ConsoleView
is not a real event loop, just a basic flow of action."""
if self.view is ConsoleView:
self.view = self.view()
self._run_console_view()
elif self.view is WxView:
app = wx.App()
self.view = self.view()
self.view._set_controller(self)
app.MainLoop()
def get_task_from_model(self, idx):
"""Needed for the WxView to communicate with the controller."""
task = self.model.get_task(idx)
self.view.show_task(task)
def _run_console_view(self):
"""Super simple event loop."""
while True:
try:
idx = self.view.select_task()
idx = int(idx)
except Exception as e:
self.view.error(e)
continue
task = self.model.get_task(idx)
self.view.show(task)
if __name__ == "__main__":
view = WxView
app = Controller(view)
app.run()
For a GUI only login generator an implementation without MVC could look a bit like this. Note that the actual calculation is done inside the window itself. This is not a good idea because we should separate responsibilities into classes!
import wx
import login_generator
class MainWindow(wx.Dialog):
def __init__(self):
wx.Dialog.__init__(self, None, title="Login Generator")
self.full_window = wx.Panel(self)
self.full_window_sizer = wx.BoxSizer(wx.VERTICAL)
self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20)
self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0)
self.full_window.SetSizer(self.full_window_sizer)
self.Show()
def create_bottom_panel(self):
bottom_panel = wx.Panel(self.full_window)
bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT)
self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup)
self.login_list.InsertColumn(0, 'username', width=200)
self.login_list.InsertColumn(1, 'password', width=200)
bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200)
return bottom_panel
def create_top_panel(self):
top_panel = wx.Panel(self.full_window)
top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_amount = wx.TextCtrl(top_panel)
self.login_complex = wx.CheckBox(top_panel, label="complex")
self.login_create = wx.Button(top_panel, label="Create")
self.login_create.Bind(wx.EVT_BUTTON, self.add_login)
top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0)
top_panel.SetSizer(top_panel_sizer)
return top_panel
def show_popup(self, event):
menu = wx.Menu()
menu.Append(1, "Copy selected items")
menu.Bind(wx.EVT_MENU, self.copy_items, id=1)
self.PopupMenu(menu)
def copy_items(self, event):
selected_items = []
for i in range(self.login_list.GetItemCount()):
if self.login_list.IsSelected(i):
username = selected_items.append(
self.login_list.GetItem(i, 0).GetText()
)
password = selected_items.append(
self.login_list.GetItem(i, 1).GetText()
)
clipdata = wx.TextDataObject()
clipdata.SetText("\n".join(selected_items))
wx.TheClipboard.Open()
wx.TheClipboard.SetData(clipdata)
wx.TheClipboard.Close()
def add_login(self, event):
amount = self.login_amount.GetValue()
complex = self.login_complex.GetValue()
try:
amount = int(amount)
except:
amount = 1
for i in range(0, amount):
username = login_generator.generate_username()
password = login_generator.generate_password(12, complex)
index = self.login_list.InsertItem(0, username)
self.login_list.SetItem(index, 1, password)
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
Now let's assume the generate username and password function take some calculation time.
We'll add in a fake time.sleep
to simulate.
import wx
import login_generator
import time
class MainWindow(wx.Dialog):
def __init__(self):
wx.Dialog.__init__(self, None, title="Login Generator")
self.full_window = wx.Panel(self)
self.full_window_sizer = wx.BoxSizer(wx.VERTICAL)
self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20)
self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0)
self.full_window.SetSizer(self.full_window_sizer)
self.Show()
def create_bottom_panel(self):
bottom_panel = wx.Panel(self.full_window)
bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT)
self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup)
self.login_list.InsertColumn(0, 'username', width=200)
self.login_list.InsertColumn(1, 'password', width=200)
bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200)
return bottom_panel
def create_top_panel(self):
top_panel = wx.Panel(self.full_window)
top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_amount = wx.TextCtrl(top_panel)
self.login_complex = wx.CheckBox(top_panel, label="complex")
self.login_create = wx.Button(top_panel, label="Create")
self.login_create.Bind(wx.EVT_BUTTON, self.add_login)
top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0)
top_panel.SetSizer(top_panel_sizer)
return top_panel
def show_popup(self, event):
menu = wx.Menu()
menu.Append(1, "Copy selected items")
menu.Bind(wx.EVT_MENU, self.copy_items, id=1)
self.PopupMenu(menu)
def copy_items(self, event):
selected_items = []
for i in range(self.login_list.GetItemCount()):
if self.login_list.IsSelected(i):
username = selected_items.append(
self.login_list.GetItem(i, 0).GetText()
)
password = selected_items.append(
self.login_list.GetItem(i, 1).GetText()
)
clipdata = wx.TextDataObject()
clipdata.SetText("\n".join(selected_items))
wx.TheClipboard.Open()
wx.TheClipboard.SetData(clipdata)
wx.TheClipboard.Close()
def add_login(self, event):
amount = self.login_amount.GetValue()
complex_bool = self.login_complex.GetValue()
try:
amount = int(amount)
except:
amount = 1
for i in range(0, amount):
username = login_generator.generate_username()
password = login_generator.generate_password(12, complex_bool)
time.sleep(1)
index = self.login_list.InsertItem(0, username)
self.login_list.SetItem(index, 1, password)
if __name__ == "__main__":
app = wx.App()
win = MainWindow()
app.MainLoop()
A clear separation of responsabilities can be acchieved via an MVC pattern and a login library.
The library code is quite straightforward and goes as follows.
It's basically the same code we did before but with added try except
blocks.
Can you tell me why I added those?
import random
import string
def load_file(filename):
"""
We load a file and make a list out of it. Note that the same function is
used for both files (both adjectives and subjects). Functions should be
made as generic as possible.
There IS a problem you can fix, some logins will have spaces in them. Try
to remove them in this function!
"""
words = []
with open(filename, "r") as fp:
lines = fp.readlines()
for line in lines:
words.append(line.strip()) # what does strip() do, what does append() do? remember CTRL+Q!
return words
def generate_username():
"""
We'll generate a random pair of adjectives and subjects from two wordlists.
You NEED to have both files in you python project for this to work! Note
the capitalize method call to make it all prettier...
"""
try:
adjectives = load_file("./adjectives.txt")
except:
adjectives = ["big", "funny", "normal", "red"]
try:
subjects = load_file("./subjects.txt")
except:
subjects = ["giraffe", "elephant", "cougar", "tiger"]
adjective = random.choice(adjectives)
subject = random.choice(subjects)
username = adjective.capitalize() + subject.capitalize()
return username
def generate_password(length=10, complictated=True):
"""
We generate a password with default settings. You can overide these by
changing the arguments in the function call.
"""
password = ""
if complictated:
chars = string.ascii_letters + string.digits + string.punctuation
else:
chars = string.ascii_letters
for i in range(0, length):
password += random.choice(chars)
return password
if __name__ == "__main__":
# let's do some testing!
username_test = generate_username()
print(username_test)
password_test = generate_password()
print(password_test)
And now the GUI code nicely split up in a model, controller and a view. The overhead is quite large but it makes the code a lot more scalable.
import wx
import login_generator
import time
import threading
import queue
class View(wx.Dialog):
def __init__(self, controller):
wx.Dialog.__init__(self, None, title="Login Generator")
self.controller = controller
self.full_window = wx.Panel(self)
self.full_window_sizer = wx.BoxSizer(wx.VERTICAL)
self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20)
self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0)
self.full_window.SetSizer(self.full_window_sizer)
self.Show()
def create_bottom_panel(self):
bottom_panel = wx.Panel(self.full_window)
bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT)
self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup)
self.login_list.InsertColumn(0, 'username', width=200)
self.login_list.InsertColumn(1, 'password', width=200)
bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200)
return bottom_panel
def create_top_panel(self):
top_panel = wx.Panel(self.full_window)
top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.login_amount = wx.TextCtrl(top_panel)
self.login_complex = wx.CheckBox(top_panel, label="complex")
self.login_create = wx.Button(top_panel, label="Create")
self.login_create.Bind(wx.EVT_BUTTON, self.submit_request)
top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0)
top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0)
top_panel.SetSizer(top_panel_sizer)
return top_panel
def show_popup(self, event):
menu = wx.Menu()
menu.Append(1, "Copy selected items")
menu.Bind(wx.EVT_MENU, self.copy_items, id=1)
self.PopupMenu(menu)
def copy_items(self, event):
selected_items = []
for i in range(self.login_list.GetItemCount()):
if self.login_list.IsSelected(i):
username = selected_items.append(
self.login_list.GetItem(i, 0).GetText()
)
password = selected_items.append(
self.login_list.GetItem(i, 1).GetText()
)
clipdata = wx.TextDataObject()
clipdata.SetText("\n".join(selected_items))
wx.TheClipboard.Open()
wx.TheClipboard.SetData(clipdata)
wx.TheClipboard.Close()
def submit_request(self, event):
amount = self.login_amount.GetValue()
complex_bool = self.login_complex.GetValue()
try:
amount = int(amount)
except:
amount = 1
self.controller.get_new_logins(amount, complex_bool)
def update_logins(self, login):
username, password = login
index = self.login_list.InsertItem(0, username)
self.login_list.SetItem(index, 1, password)
class Controller(object):
def __init__(self):
self.app = wx.App()
self.view = View(self)
self.model = Model(self)
def get_new_logins(self, amount, complex_bool):
self.model.generate_login(amount, complex_bool)
def set_new_logins(self, logins):
self.view.update_logins(logins)
class Model(threading.Thread):
def __init__(self, controller):
threading.Thread.__init__(self, target=self.main)
self.controller = controller
self.queue = queue.Queue()
self.start()
def main(self):
while True:
amount, complex_bool = self.queue.get()
username = login_generator.generate_username()
password = login_generator.generate_password(12, complex_bool)
logins = (username, password)
self.controller.set_new_logins(logins)
time.sleep(1)
def generate_login(self, amount, complex_bool):
for i in range(0, amount):
self.queue.put((amount, complex_bool))
if __name__ == "__main__":
mvc = Controller()
mvc.app.MainLoop()