I am just getting started with making basic GUI's with Tkinter.
I have previously created a script in python and I wanted to create a basic GUI for it.
My issue is I need to get the value of an entry widget to use as a parameter value, but methods online are not working for me.
This is what I am trying.
def retrieve_input():
eq_input = eq_textbox.get()
return eq_input
equation_input = retrieve_input()
eq_textbox is my entry and equation_input will be the parameter value.
from tkinter import *
window = Tk()
entry_var = StringVar() #initializing a string var
eq_textbox = Entry(window, textvariable = entry_var) #add textvariabe to store value
def retrieve_input():
eq_input = entry_var.get() #see here
return eq_input
equation_input = retrieve_input()
window.mainloop()
You need a varible to store that value... see above
Related
I want to write a program where after a user enters text and clicks a button, the text becomes a label and the button text is changed. My code is:
# Imports
import os, sys
import tkinter
"""
Tkinter program 1
text box + button + label
"""
# Button Entry
def enter(inputtedinfo, randvar, EnterMessage):
randvar = inputtedinfo.get()
EnterMessage = "Submitted!"
# Main Function
def main():
something = tkinter.Tk()
something.title("My First Tkinter Window")
something.geometry("600x400")
randvar = ""
EnterMessage = "Enter"
inputtedinfo = tkinter.StringVar()
userLabel = tkinter.Label(something, text = randvar)
userEntry = tkinter.Entry(something, textvariable = inputtedinfo)
userButton = tkinter.Button(something, text = EnterMessage, command = enter(inputtedinfo, randvar, EnterMessage))
userEntry.grid(row=0,column=0)
userLabel.grid(row=0,column=1)
userButton.grid(row=0,column=2)
something.mainloop()
sys.exit(0)
if(__name__ == "__main__"):
main()
The user input works, but clicking the button does nothing despite the fact that it is supposed to change the variables for the button and label displays. Did I mess up somewhere?
The command argument takes the name of a function. If you write the complete call with arguments, it's not the name of the function but whatever is returned by this exact function call. So, your button will not work. It will have the command None.
In order to do what you want to do, you have to make the StringVar()s accessible to the function you are calling. So, you can both get the contents of the entry and change the values of the button and the label. To do this, best add the string variables and the widgets as attributes to the toplevel you already created (something). So, they stay available to all functions and you can get and change information:
# Button Entry
def enter():
something.randvar.set(something.inputtedinfo.get())
something.userButton["text"] = "Submitted!"
# Main Function
def main():
global something
something = tkinter.Tk()
something.title("My First Tkinter Window")
something.geometry("600x400")
something.randvar = tkinter.StringVar()
something.randvar.set("")
EnterMessage = "Enter"
something.inputtedinfo = tkinter.StringVar()
userLabel = tkinter.Label(something, textvariable = something.randvar)
something.userEntry = tkinter.Entry(something, textvariable = something.inputtedinfo)
something.userButton = tkinter.Button(something, text = EnterMessage, command = enter)
something.userEntry.grid(row=0,column=0)
userLabel.grid(row=0,column=1)
something.userButton.grid(row=0,column=2)
something.mainloop()
if(__name__ == "__main__"):
main()
There are few issues in your code:
assign string to textvariable, should use StringVar instead
command=enter(...) will execute enter(...) immediately and then assign None to command option, should use lambda instead
updating strings inside enter() does not automatically update the label and the button, should use .set() on the StirngVar instead
Below is modified code:
def enter(inputtedinfo, randvar, EnterMessage):
# used .set() to update StringVar
randvar.set(inputtedinfo.get())
EnterMessage.set("Submitted!")
def main():
something = tkinter.Tk()
something.title("My First Tkinter Window")
something.geometry("600x400")
randvar = tkinter.StringVar() # changed to StringVar()
EnterMessage = tkinter.StringVar(value="Enter") # changed to StringVar()
inputtedinfo = tkinter.StringVar()
userLabel = tkinter.Label(something, textvariable=randvar) # used textvariable instead of text option
userEntry = tkinter.Entry(something, textvariable=inputtedinfo)
userButton = tkinter.Button(something, textvariable=EnterMessage, command=lambda: enter(inputtedinfo, randvar, EnterMessage))
userEntry.grid(row=0,column=0)
userLabel.grid(row=0,column=1)
userButton.grid(row=0,column=2)
something.mainloop()
This is my first attempt at a GUI. Right now I just want to be able to click a radiobutton and make it print the value I assigned to the button. However, var.get() isn't giving me anything. I tried it with IntVar (and had my values as 1 and 2 instead of "proton" and "electron") and var.get() would just give me 0. With StringVar it gives nothing (nothing prints when choosecharge is called by the radiobutton). I've tried reading stuff about radiobuttons and I wrote my code based on how I saw it done and it successfully creates the radiobuttons, but the whole point is to be able to use their values when clicked.
import tkinter as tk
def choosecharge():
print(var.get())
root = tk.Tk()
var = tk.StringVar()
proton = tk.Radiobutton(root, text = "proton", variable = var, value = "proton", command = choosecharge)
proton.pack( )
electron = tk.Radiobutton(root, text="electron", variable = var, value= "electron", command = choosecharge)
electron.pack( )
root.mainloop()
I have taken a slightly different approach to accomplish this task.
I created a dictionary of the integer radiobutton values as key and
the string that you wish to print as value.
Used a label widget to print the string in the GUI
import tkinter as tk
root = tk.Tk()
# define an IntVar
var = tk.IntVar()
# create a dictionary of key:value pair as radiobutton_value: str_name_to_print
values = {1: "proton", 2: "electron"}
# instantiate a label widget
lbl = tk.Label(root)
def choosecharge():
# update the label widgets using the dictionary
lbl.config(text=values[var.get()])
proton = tk.Radiobutton(root, text="proton", variable=var, value=1, command=choosecharge)
proton.pack(anchor=tk.W)
electron = tk.Radiobutton(root, text="electron", variable=var, value=2, command=choosecharge)
electron.pack(anchor=tk.W)
# pack the label widget below the two radiobuttons
lbl.pack()
root.mainloop()
Screenshot
I have commented the lines in the code for better understanding. I hope this solution helps you.
I'm trying to make a tkinter GUI with a certain amount of buttons and entry fields that is specified by the user, so in this code below for example if the user specifies the variable number to be 3 I want there to be 3 entry boxes and , and I want to set it up so that if I type a value into the first field and click the button next to it, I want that button to read the value from the entry field next to it. I also need to assign each entry field to a variable that will be created through the same iterative loop. However, I'm having difficulty especially in regards to mapping the buttons to the entry fields, as I always seem to run up against an error with the text "AttributeError: 'NoneType' object has no attribute 'get'". Would anyone be able to either fix my code or help me find an alternative solution to the problem? Sorry if the description's a bit confusing.
This is different from just a problem of just getting the contents of the entry widget as I need it to create a certain amount of entry widgets and buttons using iteration, and the question that my question has been marked a duplicate of doesn't explain how to iteratively map each entry field to each button. For example, if I enter 3 as the variable, I need the program to create entry field 1, entry field 2 and entry field 3 and button 1, button 2 and button 3 and then map each button to its respective entry field using iteration.
I've tried using dictionaries, but this doesn't seem to help much.
import tkinter as tk
root = tk.Tk()
number = 3
d={}
def callBack():
print(d["E{0}".format(i)].get())
return
for i in range(0,number):
d["E{0}".format(i)] = tk.Entry(root)
d["E{0}".format(i)].grid(row=i, column=0)
d["B{0}".format(i)] = tk.Button(root, text="test", command=callBack)
d["B{0}".format(i)].grid(row=i, column=1)
The solution to "'NoneType' object has no attribute 'get'" has been asked probably a hundred times on this site, and the answer is always the same.
In python, when you do x = y().z(), x will be given the value of z(). In the case of x=tk.Entry(...).grid(...), x will be None because grid(...) always returns None. The solution is to always call grid or pack or place separate from when you create a widget.
You also claim you are having problems with dictionaries, but I don't see any problem in your code other than you are making it more difficult than necessary. You can directly use i as an index without having to build up a string for the index. If you need to keep track of both buttons and entries, I recommend two variables rather than one.
Part of the problem may also have to do with the fact you're trying to do something very odd in your command. You're trying to call the get method of the entry, but that's pointless since it simply returns a value that gets thrown away. In almost all cases, the correct solution is to write a proper function rather than trying to squeeze functionality into a lambda.
Example:
def handle_click(i):
entry = entries[i]
print("the value is {}".format(entry.get()))
buttons = {}
entries = {}
for i in range(0,number):
entry = tk.Entry(root)
button = tk.Button(root, text="test", command=lambda i=i: handle_click(i))
buttons[i] = button
entries[i] = entry
entry.grid(row=i, column=0)
button.grid(row=i, column=1)
You need to save the Entry and Button before calling grid:
import tkinter as tk
number = 3
root = tk.Tk()
def get_on_click(widget_dict, entry_name):
def on_click():
result = widget_dict[entry_name].get()
print("%s = %s" % (entry_name, result))
return result
return on_click
d = dict()
for i in range(0, number):
entry_name = "E{0}".format(i)
button_name = "B{0}".format(i)
print(entry_name, button_name)
d[entry_name] = tk.Entry(root)
d[entry_name].grid(row=i, column=0)
d[button_name] = tk.Button(root, text="test", command=get_on_click(d, entry_name))
d[button_name].grid(row=i, column=1)
root.mainloop()
This should help you get started.
In your comment, you ask how to save the value in the Entry. I would create a class to handle everything:
import tkinter as tk
number = 3
root = tk.Tk()
class EntryButton(object):
def __init__(self, root, number):
self.number = number
self.entry = tk.Entry(root)
self.button = tk.Button(root, text="test", command=self.on_click)
self.entry.grid(row=number, column=0)
self.button.grid(row=number, column=1)
self.value = None
def on_click(self):
self.value = self.entry.get()
storage = dict()
for i in range(0, number):
storage[i] = EntryButton(root, i)
root.mainloop()
for i in range(0, number):
value = storage[i].value
print(f"storage[{i}] = {value}")
As you can see, this eliminates a lot of extra work.
For get text from entry
Entry.get("1.0", "end-1c")
# 1.0 for get first line.
# end-1c for if last letter space, this deletes it.
More info
I have coded both the GUI and the API separately, i tried a couple different ways of linking the two. but thought just posting the bare bone structure would be easiest that way only the code to link the two would need to be discussed.
The code for the GUI is what follows
from tkinter import *
def weather_search():
root = Tk()
root.title("Weather")
root.geometry("800x600")
app = Frame(root)
app.grid() #This puts the frame into the grid
label = Label(app, text = "Weather")
label.grid()
location_label = Label(root,text = "Enter a Location")
location_entry = Entry(root)
location_label.grid(row=1, column = 1)
location_entry.grid(row=1, column = 2)
Guessing this is what i will have to link to the API. But this is also where my limited experience is causing the problems.
user_location = location_entry.get()
print(user_location)
I tried using this but i am sure there is more that needs to be done.
root.mainloop()
weather_search()
#the code for the API is what follows
import requests
city = input("Enter: ")
url = 'http://api.openweathermap.org/data/2.5/weather?q={}&appid=46346a863b94cd3b89bad166fed78b7d&units=metric'.format(city)
res = requests.get(url)
data = res.json()
print(res)
print(data)
I am not sure if i would need a search function for once the location is entered.
As I understand it you want to get the location from the entry.
The usual way is to associate the entry with a StringVar which serves as a kind of link to the value in the entry.
An easy way of knowing when to read the entry is when the user hits the RETURN key, so I'll bind it to the entry. The callback function then reads the entry and sets the city variable.
Also I'm setting focus to entry so you won't have to click in it to enter location.
I thought the idea of putting the GUI in a function seemed a bit unusual so I rewrote it as I would have.
from tkinter import *
root = Tk()
root.title("Weather")
root.geometry("800x600")
app = Frame(root)
app.grid() #This puts the frame into the grid
label = Label(app, text = "Weather")
label.grid()
def read_entry(event): # Entry ENTER key callback function
global city
city = location.get()
print(city)
location_label = Label(root,text = "Enter a Location")
location_label.grid(row=1, column = 1)
location = StringVar() # Create a StringVar
location_entry = Entry(root, textvariable=location) # Assign textvariable
location_entry.grid(row=1, column = 2)
location_entry.bind('<Return>', read_entry) # Bind ENTER key to function
# that reads entry
location_entry.focus_set() # Sets keyboard focus to entry
root.mainloop()
Now the rest of your code can use the variable city when you exit mainloop. But you'll have to either exit mainloop or put the rest of your code inside the GUI code.
I got the assignment to build a program of a store.Now, the customers have to register to be able to buy, I made a main window that has buttons for each action I need to perform. When the user tries to register another window with the data needed to complete the registration appears. Now how do I store the data from the input-box into a list with a button?
Here's an example of how I'm setting each box that the user needs to fill:
var1 = StringVar()
var1.set("ID:")
label1 = Label(registerwindow,textvariable=var1,height = 2)
label1.grid(row=0,column=1)
ID=tkinter.StringVar()
box1=Entry(registerwindow,bd=4,textvariable=ID)
box.grid(row=0,column=2)
botonA= Button(registerwindow, text = "accept",command=get_data, width=5)
botonA.grid(row=6,column=2)
I tried setting the button to run a function that gets the input, but I't now working. Here's what I did
def get_data():
print (box1.get())
A few problems:
Unless you do import tkinter AND from tkinter import * - which you shouldn't; just choose one - your program will choke on either var1 = StringVar() or on ID=tkinter.StringVar().
Define the get_data() function before binding it to a Button.
You assigned box1 but then gridded box.
The following sample will get the box's contents, add it to a list, and print the list to the console every time you click "Accept." Replace the names of parent windows, grid locations of each widget, and so on to suit your program.
from tkinter import *
root = Tk()
root.wm_title("Your program")
mylist = []
def get_data(l):
l.append(box1.get())
print(l)
var1 = StringVar()
var1.set("ID:")
label1 = Label(root,textvariable=var1,height = 2)
label1.grid(row=0,column=0)
ID=StringVar()
box1=Entry(root,bd=4,textvariable=ID)
box1.grid(row=0,column=1)
botonA= Button(root, text = "accept",command=lambda: get_data(mylist), width=5)
botonA.grid(row=0,column=2)
root.mainloop()
to retrieve the value, you need to access the variable it is attached to, not the entry field on the screen:
def get_data():
print (ID.get())