Using tkinter to create drop down menu? - python

I'm new to Python, and I am trying to create a GUI that displays a list of characteristics when an item in a drop down menu is selected. I want the text to be displayed under the drop down menu. Here is what I have so far, but all it provides is an empty box:
import tkinter
import tkinter as tk
#creates box
window =tkinter.Tk()
frame= tkinter.Frame(window)
frame.pack()
window.geometry("%dx%d+%d+%d" % (330, 80, 200, 150))
window.title("Breeds and Characteristics")
#data
data=('Abyssinian','American-Bobtail','American-Curl')
Output1 ="Aloof,Intelligent,Diseased"
Output2= "Affectionate,Intelligent,Diseased"
Output3= "Affectionate,Dull,Healthy"
display = Label(window, text="")
#create a dropdown list
p = tkinter.Combobox(window, textvariable=var, values=data)
p.pack()
def chars():
for values in p:
if item == 'Abyssinian':
print (Output1)
elif item == 'American-Bobtail':
print (Output2)
elif item == 'American-Curl':
print (Output3)
#starts dropdown box at first cat
var = tkinter.StringVar()
var.set('Abyssinian')
#updates text
def boxtext():
display.configure(text=(chars))
display.pack()
#button to view characteristics
button = Button(window, text='View Characteristics', command=select)
button.pack(side='left', padx=20, pady=10)
window.mainloop()

The drop down widget is called tkinter.OptionMenu. You would need to make a function that can update the Label and provide that function to the OptionMenu as a callback. Like this:
import tkinter
#creates box
window =tkinter.Tk()
window.geometry("%dx%d+%d+%d" % (330, 80, 200, 150))
window.title("Breeds and Characteristics")
#data
data={
'Abyssinian':"Aloof,Intelligent,Diseased",
'American-Bobtail':"Affectionate,Intelligent,Diseased",
'American-Curl':"Affectionate,Dull,Healthy",
}
#updates text
def boxtext(new_value):
display.config(text = data[new_value])
#create a dropdown list
var = tkinter.StringVar()
var.set('Abyssinian')
p = tkinter.OptionMenu(window, var, *data, command=boxtext)
p.pack()
display = tkinter.Label(window)
display.pack()
window.mainloop()

Related

python issue adds a new label

take a look at this code
well it happens to just add another label for no reason
import tkinter
from tkinter import *
clicks = 1
def click_count():
global clicks
# making the label that shows how many idk you have
label = Label(frame, text="you have " + str(clicks), font=(('Courrier'), 32))
label.pack()
clicks += 1
label.pack()
#generating the window
root = tkinter.Tk()
root.geometry('500x500')
#making the expandable frame
frame = Frame(root)
frame.pack(expand=YES)
#making the button
button = Button(frame, text= "click", font=(('Courrier'), 32), command=click_count)
button.pack()
root.mainloop()
and then i tried this
and i also tried to remove the label.pack at the end
but it still does the same thing which is adding another label
import tkinter
from tkinter import *
clicks = 1
def click_count():
global clicks
# making the label that shows how many idk you have
label = Label(frame, text="you have " + str(clicks), font=(('Courrier'), 32))
label.pack()
label.destroy()
clicks += 1
label.pack()
#generating the window
root = tkinter.Tk()
root.geometry('500x500')
#making the expandable frame
frame = Frame(root)
frame.pack(expand=YES)
#making the button
button = Button(frame, text= "click", font=(('Courrier'), 32), command=click_count)
button.pack()
root.mainloop()
i was expecting it to add a nmber to the label but it just shows another label
It does not add a Label for no reason. It adds the label because that's what your function tells it to do. Each time you click the button, the function is executed that creates and packs a new Label.
What you should do is create the label at the onset and link it to a variable. Then, you can change the value of this variable in the function.
Also, you don't have to import tkinter twice and it's sensible to update the clicker first and then display the result instead of showing the last value it had. Your approach works in such a small program but the value of clicks will always be one higher than displayed. So, you may get into problems when you use the value.
from tkinter import *
def click_count():
global clicks
clicks += 1
click_counter.set("you have " + str(clicks))
#Initiate root
root = Tk()
root.geometry('500x500')
#Set initial values for click counter
clicks = 0
click_counter = StringVar()
click_counter.set("you have 0")
#making the expandable frame
frame = Frame(root)
frame.pack(expand=YES)
# making the label that shows how many idk you have
label = Label(frame, textvariable=click_counter, font=(('Courrier'), 32)) ## The label gets updated, whenever the value of click_counter changes.
label.pack()
#making the button
button = Button(frame, text= "click", font=(('Courrier'), 32), command=click_count)
button.pack()
root.mainloop()

How do I include a calculation function in a menu item in Tkinter?

I created a menu item and want to run a function within that menu which will run a simple calculation based on a entry. When I run the code in my terminal, I can see my window and the menu item with the entry widget. But, I don't see anything and result from my function. I don't get an error from the terminal. Below is my code. Where did I mess in my code?
from tkinter import *
root = Tk()
root.title(" My calculator")
root.geometry("400x400")
# Defining calculator 1 function
def calculator_1():
# creating an entry
frame1.pack(fill="both",expand=1)
e1 =Entry(frame1)
e1.pack(pady=5)
# Defining the formula function
def formula():
res = (int(e1.get()) + 1)
myText.set(res)
# creating a calculate button
my_button = Button(frame1, text="Click to calculate", command=formula)
my_button.pack(pady=5)
myText=StringVar()
result=Label(frame1, text=" your results is ", textvariable =myText)
result.pack(pady=5)
label_result =Label(frame1, text= "Your result is")
label_result.pack(pady=5)
# Define Main menu
my_menu = Menu(root)
root.config(menu=my_menu)
#create menu items
math_menu = Menu(my_menu)
my_menu.add_cascade(label="MathCards",menu=math_menu)
math_menu.add_command(label="Calculator 1",command=calculator_1)
math_menu.add_separator()
math_menu.add_command(label="Exit", command=root.quit)
# Creating a frame
frame1 = Frame(root, width =400, height=400)
root.mainloop()

Python: 'NoneType' object has no attribute 'get'

I'm creating a GUI in python using tkinter and am having trouble when running it. I have an entry box widget, a radiobutton widget, and a button widget. When I press the button, what I want is the user to type a number into the entry box and select an option from the list of radiobuttons. When the user presses the button, I'd like the values to be retrieved and displayed in the other frame for testing. What I get instead is when the button gets pressed, I get the error 'NoneType' object has no attribute 'get'. The error is referring to the value inside of the entry box: self.tune_entry
The code I have is as follows:
SA_main.py
import os
import tkinter as tk
from tkinter import ttk
from tkinter import font
import SA_gui
def main():
x_vals = [0,1,2,3,4]
y_vals = [0,1,2,3,4]
root = SA_gui.tk.Tk()
UI = SA_gui.Window(root, x_vals, y_vals)
root.mainloop()
if __name__ == "__main__":
main()
SA_gui.py
import os
import tkinter as tk
from tkinter import ttk
from tkinter import font
# Class to define, setup, and build the GUI
class Window:
# Dimensions of the GUI
HEIGHT = 600
WIDTH = 1200
# Colors for main layout
bg_color = "#B0E0E6"
frame_color1 = "#73B1B7"
white_color = "#FFFFFF"
def __init__(self, master, x_vals, y_vals):
# Take in the lists of files for later use
self.x_vals = x_vals
self.y_vals = y_vals
#--------------------------------------------------------------
# Define and create the window
self.master = master
master.title("Signal Analysis")
master.geometry("{}x{}".format(Window.WIDTH, Window.HEIGHT))
# Create and place the background frame
self.bg_frame = tk.Frame(self.master, bg=Window.bg_color, bd=5)
self.bg_frame.place(relwidth=1, relheight=1)
# Create the main title
self.main_title = tk.Label(self.bg_frame, text="Software Defined Radio Signal Analysis",
bg=Window.bg_color, font=("Courier", 14))
self.main_title.pack(side="top")
#--------------------------------------------------------------
# Create and place the frame for tuning
self.tune_frame = tk.Frame(self.bg_frame, bg=Window.frame_color1, bd=4)
self.tune_frame.place(relx=0.05, rely=0.1, relwidth=0.2428, relheight=0.8)
# Create and place the title for the tuning frame
self.tune_title = tk.Label(self.tune_frame, text="Tune", bg=Window.frame_color1, font=
("Courier", 11))
self.tune_title.place(relwidth=1, anchor="nw")
# Create and place the contents of the tuning frame
self.tune_cont = tk.Frame(self.tune_frame, bg=Window.white_color, bd=4)
self.tune_cont.place(relx=0.05, rely=0.05, relwidth=0.9, relheight=0.925)
#Label for frequency entry
self.tune_label = tk.Label(self.tune_cont, text='Enter carrier frequency: (kHz)',
bg=Window.white_color)
self.tune_label.place(relx=0.025, rely=0)
#Entry Box for frequency entry
self.tune_entry = tk.Entry(self.tune_cont)
self.tune_entry.place(relx=0.025, rely=0.075, relwidth=0.95, relheight=0.05)
#Label for divider
self.tune_div = ttk.Separator(self.tune_cont, orient="horizontal")
self.tune_div.place(rely=0.175, relwidth=1)
#Label for display mode
self.disp_label = tk.Label(self.tune_cont, text='Select Display:', bg=Window.white_color)
self.disp_label.place(relx=0.025, rely=0.2)
#Variable for radiobuttons
self.var = tk.IntVar(self.tune_cont).set("1")
#Radio Button for Spectral Analysis
self.SA_select = tk.Radiobutton(self.tune_cont, text="Spectral
Analysis",bg=Window.white_color, padx=20, variable=self.var, value=1)
self.SA_select.place(relx=0.025, rely=0.275)
#Radio Button for Option 2
self.opt2_select = tk.Radiobutton(self.tune_cont, text="Option 2",bg=Window.white_color,
padx=20, variable=self.var, value=2)
self.opt2_select.place(relx=0.025, rely=0.35)
#Radio Button for Option 3
self.opt3_select = tk.Radiobutton(self.tune_cont, text="Option 3",bg=Window.white_color,
padx=20, variable=self.var, value=3)
self.opt3_select.place(relx=0.025, rely=0.425)
#Button for selection
self.tune_button = ttk.Button(self.tune_cont, text="Enter", command=lambda:
self.print_selected(self.var.get(), self.tune_entry.get()))
self.tune_button.place(relx= 0.775, rely=0.9, relwidth=0.2, relheight=0.075)
#-----------------------------------------------------------------
# Create and place the frame for the plot
self.plot_frame = tk.Frame(self.bg_frame, bg=Window.frame_color1, bd=4)
self.plot_frame.place(relx=0.3428, rely=0.1, relwidth=0.6071, relheight=0.8)
# Create and place the title for the plot frame
self.plot_title = tk.Label(self.plot_frame, text="Plot", bg=Window.frame_color1, font=
("Courier", 11))
self.plot_title.place(relwidth=1, anchor="nw")
# Create and place the contents of the plot frame
self.plot_cont = tk.Frame(self.plot_frame, bg=Window.white_color, bd=4)
self.plot_cont.place(relx=0.025, rely=0.05, relwidth=0.95, relheight=0.925)
def print_selected(self, disp, freq):
if disp == 1:
disp_mode = "Spectral Analysis"
elif disp == 2:
disp_mode = "Option 2"
else:
disp_mode = "Option 3"
#Label for this test
self.prnt_label = tk.Label(self.plot_cont, text="Display: " + disp_mode + ", Center Freq: " +
freq, bg=Window.white_color)
self.prnt_label.place(relx=0.025, rely=0.2)
Any help to resolve this issue is greatly appreciated!
Consider this code:
self.var = tk.IntVar(self.tune_cont).set("1")
Anytime you do x=y().z() python assigns the return value of z() to x. Thus, in your code you're assiging the result of .set("1") to self.var. The set method is returning None so self.var is None. Thus, when you later try to call self.var.get() it's the same as doing None.get().
If you want to initialize a variable at the time of creation, there is no need to call set. Also, while it works to pass a string, if you're setting an IntVar you really ought to be setting it to an integer.
self.var = tk.IntVar(value=1)

How to get widget name in event?

from tkinter import *
main = Tk()
def flipper(event):
# I'd like to do this:
#if widgetname == switcher:
#do stuff
#if widgetname == switcher1:
#do stuff
return
switcher = Label(main, bg='white', text="click here", font="-weight bold")
switcher.grid()
switcher.bind("<Button-1>", flipper)
switcher1 = Label(main, bg='white', text="click here", font="-weight bold")
switcher1.grid()
switcher1.bind("<Button-1>", flipper)
switcher2 = Label(main, bg='white', text="click here", font="-weight bold")
switcher2.grid()
switcher2.bind("<Button-1>", flipper)
switcher3 = Label(main, bg='white', text="click here", font="-weight bold")
switcher3.grid()
switcher3.bind("<Button-1>", flipper)
switcher4 = Label(main, bg='white', text="click here", font="-weight bold")
switcher4.grid()
switcher4.bind("<Button-1>", flipper)
switcher5 = Label(main, bg='white', text="click here", font="-weight bold")
switcher5.grid()
switcher5.bind("<Button-1>", flipper)
main.mainloop()
In my event function I'd like to do different things based on the label that is clicked. What im stumped on is that I can only get the identifier number of the widget that is clicked, not the name. If I could get the identifier of all my widgets then I could do:
def flipper(event):
if event.widget == switcher.identifier():
do stuff
but I can't find how to get the id of a specified widget either...
How can I get the name of a widget by its identifier (event.widget())?
Or how can I get the identifier of a specified widget name?
If neither are possible, then I'd have to make a different function and bind for each label which is a lot of work that hopefully is not necessary.
Edit:
from tkinter import *
main = Tk()
def flipper(event, switch):
if switch.widget == 's1':
print("got it")
switcher = Label(main, bg='white', text="click here", font="-weight bold")
switcher.grid()
switcher.bind("<Button-1>", flipper)
switcher.widget = 's1'
main.mainloop()
You can't get the variable name that the widget is assigned to, that would be relatively useless. A widget could be assigned to more than one variable, or none at all.
Getting the label text
You have access to the actual widget, and you can use that to get the text that is on the label. Your example shows that all labels are the same, so this might not be useful to you:
def flipper(event):
print("label text:", event.widget.cget("text"))
Using a custom widget name
You can also give a widget a name. You can't get back precisely the name, but you can come very close. For example, if you create a label like this:
switcher = Label(main, name="switcher", bg='white', text="click here", font="-weight bold")
You can get the string representation of the widget by splitting on "." and taking the last value:
def flipper(event):
print("widget name:", str(event.widget).split(".")[-1])
Passing a name via the binding
Finally, you can set up your bindings such that the name is sent to the function:
switcher.bind("<Button-1>", lambda event: flipper(event, "switcher"))
switcher1.bind("<Button-1>", lambda event: flipper(event, "switcher1"))
You can use event.widget to get standard parameters from clicked widget
example:
import tkinter as tk
def callback(event):
print(event.widget['text'])
main = tk.Tk()
switcher = tk.Label(main, text="click here")
switcher.grid()
switcher.bind("<Button-1>", callback)
main.mainloop()
You can assign own variables to widgets
switcher.extra = "Hello"
and then get it
event.widget.extra
example:
import tkinter as tk
def callback(event):
print(event.widget['text'])
print(event.widget.extra)
main = tk.Tk()
switcher = tk.Label(main, text="click here")
switcher.grid()
switcher.bind("<Button-1>", callback)
switcher.extra = "Hello"
main.mainloop()
You can use lambda to bind function with arguments
bind("<Button-1>", lambda event:callback(event, "Hello"))
example:
import tkinter as tk
def callback(event, extra):
print(event.widget['text'])
print(extra)
main = tk.Tk()
switcher = tk.Label(main, text="click here")
switcher.grid()
switcher.bind("<Button-1>", lambda event:callback(event, "Hello"))
main.mainloop()
I had the same issue I found easy way was to use bind method.
apparent name property is private but can be accessed via _name
This is useful if you plan to generate widgets dynamically at runtime
# Import Module
from tkinter import *
# create root window
root = Tk()
# root window title and dimension
root.title("Welcome to Test window")
# Set geometry (widthxheight)
root.geometry('350x200')
#adding a label to the root window
lbl = Label(root, text = "Press a button")
lbl.grid()
#define mouse up event
def mous_up(ev:Event):
#get calling widget from event
sender:Button = ev.widget
#set label text
lbl.configure(text = sender._name + " up")
#read foreground color from button
#If red make green, else make red
if sender.cget('fg') == "red":
#normal color
sender.configure(fg='lime')
#mouse over color
sender.configure(activeforeground='green')
else:
#normal color
sender.configure(fg="red")
#mouse over color
sender.configure(activeforeground='darkred')
#define mouse down event
def mous_down(ev:Event):
lbl.configure(text = str(ev.widget._name) + " down")
# button widget with red color text
# inside
btn = Button(root, text = "Click me" ,
fg = "red",name = "button-A")
#bind mouse up and mouse down events
btn.bind('<ButtonRelease-1>',mous_up)
btn.bind('<Button-1>',mous_down)
# set Button grid
btn.grid(column=0, row=1)
#Create another button
btn = Button(root, text = "Click me2" ,
fg = "red",name="button2")
#bind mouse up and mouse down events
btn.bind('<ButtonRelease-1>',mous_up)
btn.bind('<Button-1>',mous_down)
#absolute placement of button instead of
#using grid system
btn.place(x=50,y=100)
# all widgets will be here
# Execute Tkinter
root.mainloop()
Quick and dirty - you could have the function check a switcher attribute.
def flipper(event, switch):
if switch.widget == 's1':
do_stuff
return stuff
if switch.widget == 's2':
do_stuff
return stuff
switcher1.widget = 's1'
switcher2.widget = 's2'
I know this is an old post, but I had the same problem and I thought I should share a solution in case anyone is interested. You can give your widget a name by creating a subclass of the widget. E.g. "Button" is a widget. You can make a child widget "MyButton" which inherits from button and then add an instance variable to it (e.g. name, uniqueID etc.)
Here is a code snippet
class MyButton(Button):
def __init__(self, master = None, textVal = "", wName = ""):
Button.__init__(self, master, text = textVal)
self.widgetID = wName #unique identifier for each button.
When you want to create a new button widget, use
b = MyButton(.....),
instead of
b = Button(.......)
This way, you have all the functionality of a button, plus the unique identifier.

How to change the colour of everything in a tkinter GUI at once

I have some code (as shown below) which prompts the user to select which colour to change the GUI to. But my problem is that it only changes the background. I'd like to know if there's a way to change the background of every label and button at once or do I have to change each label/button individually.
import tkinter
window = tkinter.Tk()
colour_frame = tkinter.Frame(window)
options_frame = tkinter.Frame(window)
def colours():
options_frame.pack_forget()
red.pack()
orange.pack()
back_button.pack()
colour_frame.pack()
def back():
options_frame.pack()
colour_frame.pack_forget()
def make_red():
window.configure(background="red")
def make_orange():
window.configure(background="orange")
colour_button = tkinter.Button(options_frame, text="Appearance", command=colours)
red = tkinter.Button(colour_frame, text="RED", command=make_red)
red.configure(bg = "red")
orange = tkinter.Button(colour_frame, text="ORANGE", command=make_orange)
orange.configure(bg = "orange")
back_button = tkinter.Button(colour_frame, text="Back", command=back)
window.mainloop()
You can make a list containing all your widgets you want to change
myWidgets = [button1, label1, ... ] # List of widgets to change colour
for wid in myWidgets:
wid.configure(bg = newColour)
Here's an example code of changing the background colour of multiple labels at once.
import tkinter as tk
# Change all label backgrounds
def change_colour():
c = user.get() #Get the entered text of the Entry widget
for wid in widget_list:
wid.configure(bg = c)
# Create GUI
root = tk.Tk()
tk.Label(root, text='Enter a colour').pack()
user = tk.Entry(root)
user.pack()
label_frame = tk.Frame(root)
label_frame.pack()
btn = tk.Button(root, text='Change Colour', command = change_colour)
btn.pack()
widget_list = [user, btn] # Add defined widgets to list
#Dynamicly create labels for example
for x in range(10):
lbl = tk.Label(label_frame, text='Label '+str(x))
lbl.pack(side = tk.LEFT)
widget_list.append(lbl) #Add widget object to list
root.mainloop()
Or if you have a Frame already containing all the widgets you want to change, then you can use this instead.
parent_widget.winfo_children() will return a list containing all the widgets stored inside the parent widget
def change_colour():
c = user.get()
for wid in label_frame.winfo_children():
wid.configure(bg = c)
Try using ttk for some of your GUI elements. ttk allows you to create styles for widgets and update the style to all widgets at once (at least for those that have the same style). You may need to mix the usage of ttk and tkinter, but it should make things a bit easier in the long run. Here is an example I made:
import tkinter as tk
from tkinter import ttk
root = tk.Tk()
# Creating a style for the buttons
color_style_button = ttk.Style()
color_style_button.configure("color.TButton", foreground="red")
def change_color(color):
# This function changes the style to all buttons using the "color.Button style"
if color == "red":
color_style_button.configure("color.TButton", foreground="red")
elif color == "blue":
color_style_button.configure("color.TButton", foreground="blue")
elif color == "green":
color_style_button.configure("color.TButton", foreground="green")
frame_a = ttk.Frame(root)
frame_a.pack()
red_button = ttk.Button(frame_a, text="Red", command=lambda: change_color("red"), style="color.TButton")
red_button.pack()
blue_button = ttk.Button(frame_a, text="Blue", command=lambda: change_color("blue"), style="color.TButton")
blue_button.pack()
green_button = ttk.Button(frame_a, text="Blue", command=lambda: change_color("green"), style="color.TButton")
green_button.pack()
root.mainloop()
I recommend checking out this site to learn more about ttk and styles.

Categories