I am making a sort of todo app using tkinter. For this I want to generate checkbox dynamically and I have successfully done this using a function but I also want to delete those checkboxes when user press clear button. How can this be done.
name=Stringvar()
ent=Entry(root,textvariable=name).pack()
def clear(ent):
ent.pack_forget()
def generate():
k=name.get()
c=Checkbutton(root,text=k)
c.pack()
btn1=Button(root,text="Submit",command=generate)
btn1.pack()
btn2=Button(root,text="Clear",command=clear)
btn2.pack()
I want to delete the checkbox but I cannot do so as function clear does not read c.pack_forget()
It is very simple to do just store all the objects of Checkbutton created in the generate() function like so
First you need a List.
Tip: Use Dictionary if you need to store more information about the object.
Append each Checkbutton created. (List.append(c)..)
Then pack_forget() the Checkbutton from the List with the help of for loop. If you are not planning to use those Check buttons in future then use destroy() instead of pack_forget() .
Here is the code:
from tkinter import *
root = Tk()
name = StringVar()
check_box_list = []
ent=Entry(root,textvariable=name).pack()
def clear():
for i in check_box_list:
i.pack_forget() # forget checkbutton
# i.destroy() # use destroy if you dont need those checkbuttons in future
def generate():
k=name.get()
c=Checkbutton(root,text=k)
c.pack()
check_box_list.append(c) # add checkbutton
btn1=Button(root,text="Submit",command=generate)
btn1.pack()
btn2=Button(root,text="Clear",command=clear)
btn2.pack()
mainloop()
If you want to remove each one separately instead of clear all then try this.
from tkinter import *
root = Tk()
name = StringVar()
check_box_list = []
ent=Entry(root,textvariable=name).pack()
def clear():
for i in check_box_list:
if i.winfo_exists(): # Checks if the widget exists or not
i.pack_forget() # forget checkbutton
# i.destroy() # use destroy if you dont need those checkbuttons in future
def generate():
k=name.get()
f = Frame(root)
Checkbutton(f, var=StringVar(), text=k).pack(side='left')
Button(f, text='✕', command=f.destroy).pack(side='left')
check_box_list.append(f) # add Frame
f.pack()
btn1=Button(root,text="Submit",command=generate)
btn1.pack()
btn2=Button(root,text="Clear All",command=clear)
btn2.pack()
mainloop()
Related
Generator functions promise to make some code easier to write. But I don't always understand how to use them.
Let's say I have a Fibonacci generator function fib(), and I want a tkinter application that displays the first result. When I click on a button "Next" it displays the second number, and so on. How can I structure the app to do that?
I probably need to run the generator in a thread. But how do I connect it back to the GUI?
You don't need a thread for this particular problem. You just need to instantiate the generator, then use next to get a new value each time the button is pressed.
Here's a simple example:
import tkinter as tk
def fibonacci_sequence():
'''Generator of numbers in a fibonacci sequence'''
a,b = 1,1
while True:
yield a
a,b = b, a+b
def do_next():
'''Updates the label with the next value from the generator'''
label.configure(text=next(generator))
root = tk.Tk()
label = tk.Label(root, text="")
button = tk.Button(root, text="Next", command=do_next)
label.pack(side="top")
button.pack(side="bottom")
# Initialize the generator, then us it to initialize
# the label
generator = fibonacci_sequence()
do_next()
root.mainloop()
Not expert in tkinter but one way is to use function StringVar to be able to update its value and using text box for output.
Try this out, hope it gives you a clue.
import tkinter as tk
fibo_list = [1,1]
def fibo():
fibo_list.append(fibo_list[-1] + fibo_list[-2])
variable.set(fibo_list[-1])
show_fibo_value()
def show_fibo_value():
text_box.insert(index='end',chars=variable.get()+'\n')
root = tk.Tk()
variable = tk.StringVar()
text_box = tk.Text()
text_box.pack()
button = tk.Button(root, text="Next", command=fibo)
button.pack()
root.mainloop()
I would like to write a tkinter app that will automatically update a value based on the current state of the OptionMenu object. Here's what I have so far
from tkinter import *
root = Tk()
def show():
myLabel=Label(root,text=clicked.get()).pack()
clicked=StringVar()
clicked.set("1")
drop = OptionMenu(root,clicked,"1","2","3")
drop.pack()
myButton = Button(root,text="show selection",command=show)
root.mainloop()
In this version, the text can only be updated by clicking a button. How can I make the text update automatically, without this "middle man"?
You can simply assign clicked to the textvariable of the Label, then whenever an option is selected, the label will be updated:
import tkinter as tk
root = tk.Tk()
clicked = tk.StringVar(value="1")
drop = tk.OptionMenu(root, clicked, "1", "2", "3")
drop.pack()
tk.Label(root, textvariable=clicked).pack()
root.mainloop()
After changing some things, i got it working.
It is better to use the config() function to change item's attributes, and another important thing is to not pack() the objects (the Label, in this case) in the same line that the variable declaration.
Like so, you'll be able to change the text. Here is your code updated!
from tkinter import *
def show():
myLabel.config(text = clicked.get())
root = Tk()
clicked=StringVar( value="1")
myLabel=Label(root, text="click the button at the bottom to see this label text changed")
myLabel.pack()
drop = OptionMenu(root, clicked, "1","2","3")
drop.pack()
myButton = Button(root, text="show selection", command=show)
myButton.pack()
root.mainloop()
I want a checkbox that when check, creates a scrolled text widget and when unchecked, removes the widget.
Currently it creates the widget only once I've checked the box and then unchecked it, and then when checked again, it does nothing and when unchecked again, it creates a second widget below.
I've tried different ways of coding it but I can't figure out what I'm doing wrong.
# Creates Normal Checkbutton
chk_state = BooleanVar()
chk_state.set(False) # set check state
chk = Checkbutton(window, text='Normal Entries', var=chk_state)
chk.place(x=0, y=0)
#Checks Checkbutton State
def chk_checked(event):
txt = scrolledtext.ScrolledText(window, height=15, width=35)
if chk_state.get():
txt.insert(END, 'Paste Normal Entries Here...')
txt.pack(anchor='nw', padx=50, pady=50)
elif txt.winfo_exists():
txt.pack_forget()
else:
pass
#Event when checkbox checked
chk.bind('<Button-1>', chk_checked)
You can try as this
import tkinter as tk
from tkinter.scrolledtext import ScrolledText
def chk_checked():
global txt
if chk_state.get():
txt = ScrolledText(window, height=15, width=35)
txt.insert(tk.END, 'Paste Normal Entries Here...')
txt.pack(anchor='nw', padx=50, pady=50)
else:
txt.pack_forget()
window = tk.Tk()
chk_state = tk.BooleanVar()
chk_state.set(False) # set check state
chk = tk.Checkbutton(window, text='Normal Entries', var=chk_state, command=chk_checked)
chk.place(x=0, y=0)
txt = None
window.mainloop()
This isn't the best way for do that, maybe you can create a class, i think that would be better.
The problem with your code is that each time that you click the CheckButton the function chk_checked(event) creates a new ScrolledText and after works on it instead working on the ScrolledText that was created previously. You have to declare a global variable (instead of a local variable) in wich you store the ScrolledText that you want to use and work only with it
I created a button that retrieves a list from a DataFrame based on some input from a text field. Everytime the button is pressed, the list will be refreshed. I output the list (as an OptionMenu) in a separate Frame (outputFrame). However, every time I press this button, a new OptionMenu is added to the Frame (instead of overwriting the previous one). How can I make sure that the content of 'ouputFrame' is overwritten each time I press the button?
# start
root = Tkinter.Tk()
# frames
searchBoxClientFrame = Tkinter.Frame(root).pack()
searchButtonFrame = Tkinter.Frame(root).pack()
outputFrame = Tkinter.Frame(root).pack()
# text field
searchBoxClient = Tkinter.Text(searchBoxClientFrame, height=1, width=30).pack()
# function when button is pressed
def getOutput():
outputFrame.pack_forget()
outputFrame.pack()
clientSearch = str(searchBoxClient.get(1.0, Tkinter.END))[:-1]
# retrieve list of clients based on search query
clientsFound = [s for s in df.groupby('clients').count().index.values if clientSearch.lower() in s.lower()]
clientSelected = applicationui.Tkinter.StringVar(root)
if len(clientsFound) > 0:
clientSelected.set(clientsFound[0])
Tkinter.OptionMenu(outputFrame, clientSelected, *clientsFound).pack()
else:
Tkinter.Label(outputFrame, text='Client not found!').pack()
Tkinter.Button(searchButtonFrame, text='Search', command=getOutput).pack()
root.mainloop()
We can actually update the value of the OptionMenu itself rather than destroying it (or it's parent) and then redrawing it. Credit to this answer for the below snippet:
import tkinter as tk
root = tk.Tk()
var = tk.StringVar(root)
choice = [1, 2, 3]
var.set(choice[0])
option = tk.OptionMenu(root, var, *choice)
option.pack()
def command():
option['menu'].delete(0, 'end')
for i in range(len(choice)):
choice[i] += 1
option['menu'].add_command(label=choice[i], command=tk._setit(var, choice[i]))
var.set(choice[0])
button = tk.Button(root, text="Ok", command=command)
button.pack()
root.mainloop()
I am trying to create a window with a line label, an entry field, a current value label, and an "Update Value" button.
Here is an example:
This is what I have so far. I can get the entered value to print to console, but I can't seem to work out how to get an entered value and change the currentValue Label to reflect that value by pressing the button:
from tkinter import*
main=Tk()
#StringVar for currentValue in R0C2
currentValue = StringVar(main, "0")
#Called by the setValues button, looks for content in the entry box and updates the "current" label
def setValues():
content = entry.get()
print(content)
#This kills the program
def exitProgram():
exit()
#Title and window size
main.title("Title")
main.geometry("350x200")
#Descriptions on the far left
Label(main, text="Duration (min): ").grid(row=0, column=0)
#Entry boxes for values amidship
entry=Entry(main, width=10)
entry.grid(row=0, column=1)
#Displays what the value is currently set to.
currentValue = Label(textvariable=currentValue)
currentValue.grid(row=0,column=2)
#Takes any inputted values and sets them in the "Current" column using def setValues
setValues=Button(text='Set Values',width=30,command=setValues)
setValues.grid(row=9, column=0, columnspan=2)
#Red button to end program
exitButton=Button(main, text='Exit Program',fg='white',bg='red',width=30, height=1,command=exitProgram)
exitButton.grid(row=20, column = 0, columnspan=2)
main.mainloop()
There are a couple of problems with your code.
Firstly, you are overwriting the setValues function with the setValues Button widget, and similarly, you are overwriting the currentValue StringVar with the currentValue Label.
To set a StringVar, you use its .set method.
Don't use plain exit in a script, that's only meant to be used in an interactive interpreter session, the proper exit function is sys.exit. However, in a Tkinter program you can just call the .destroy method of the root window.
Here's a repaired version of your code.
import tkinter as tk
main = tk.Tk()
#StringVar for currentValue in R0C2
currentValue = tk.StringVar(main, "0")
#Called by the setValues button, looks for content in the entry box and updates the "current" label
def setValues():
content = entry.get()
print(content)
currentValue.set(content)
#This kills the program
def exitProgram():
main.destroy()
#Title and window size
main.title("Title")
main.geometry("350x200")
#Descriptions on the far left
tk.Label(main, text="Duration (min): ").grid(row=0, column=0)
#Entry boxes for values amidship
entry = tk.Entry(main, width=10)
entry.grid(row=0, column=1)
#Displays what the value is currently set to.
currentValueLabel = tk.Label(textvariable=currentValue)
currentValueLabel.grid(row=0,column=2)
#Takes any inputted values and sets them in the "Current" column using def setValues
setValuesButton = tk.Button(text='Set Values',width=30,command=setValues)
setValuesButton.grid(row=9, column=0, columnspan=2)
#Red button to end program
exitButton = tk.Button(main, text='Exit Program',fg='white',bg='red',width=30, height=1,command=exitProgram)
exitButton.grid(row=20, column = 0, columnspan=2)
main.mainloop()
BTW, it's a Good Idea to avoid "star" imports. Doing from tkinter import * dumps 130 names into your namespace, which is unnecessary and creates the possibility of name collisions, especially if you do star imports from several modules. It also makes the code less readable, since the reader has remember which names you defined and which ones came from the imported module(s).
In my opinion the easiest way to do this would be using an object orientated method. This way you could declare a button with a command that calls a def which runs self.label.configure(text=self.entry.get()).
This can be seen below:
import tkinter as tk
class App:
def __init__(self, master):
self.master = master
self.label = tk.Label(self.master)
self.entry = tk.Entry(self.master)
self.button = tk.Button(self.master, text="Ok", command=self.command)
self.label.pack()
self.entry.pack()
self.button.pack()
def command(self):
self.label.configure(text=self.entry.get())
root = tk.Tk()
app = App(root)
root.mainloop()
The above creates a label, entry and button. The button has a command which calls a def within the class App and updates the value of the label to be the text contained within the entry.
This all works very smoothly and cleanly and more importantly is drastically easier (in my opinion) to read and update in the future.
From your code you are setting the 'currentValue', which is a StringVar:
#StringVar for currentValue in R0C2
currentValue = StringVar(main, "0")
to an object Label further down in your code. You cannot do this!
#Displays what the value is currently set to.
currentValue = Label(textvariable=currentValue) ** this line is wrong
currentValue.grid(row=0,column=2)
You should name the label something different like:
#Displays what the value is currently set to.
lblCurrentValue = Label(textvariable=currentValue)
lblCurrentValue.grid(row=0,column=2)
Then in your "setValues" method you should use 'StringVar.set(value) to update the label like so:
def setValues():
content = entry.get()
currentValue.set(entry.get())------------------Here I set the value to the entry box value
print(content)
I tend to avoid stringVar and just use:
Label.config(text='*label's text*')
If you need more help I can post you my solution but try and solve it first becasue its the best way to learn. My tip is to make sure you are using correct naming conventions. In tkinter I tend to use lbl..., entryBox... etc before widgets so I know what they are and not to confuse them with variables.