Dear fellow programmers,
I use Python 2.7 on windows 10 64 bits.
I have an issue with a Tkinter window. In a parent program, I want to save a file and I ask the name of the file in a Tkinter window. My problem is that I don't succeed to get this name outside of the Tkinter window. Here is the Python code:
from Tkinter import *
globalFilename = ""
class Master:
def __init__(self, top):
self.filename = ""
frame_e = Frame(top)
frame_e.pack()
self.t_filename = StringVar()
entry = Entry(frame_e, textvariable=self.t_filename, bg="white")
entry.pack()
entry.focus_force()
saveButton = Button(frame_e, text="Save", command=self.on_button)
saveButton.pack(side=BOTTOM, anchor=S)
def on_button(self):
self.filename = self.t_filename.get()
print self.filename
root.quit()
root.destroy()
root = Tk()
root.geometry("100x100+100+50")
M = Master(root)
print M.filename
root.mainloop( )
print M.filename
globalFilename = M.filename
print globalFilename
All print statements in this code give nothing when I enter any text into the Entry textbox. This is not what I expect. If I enter "test" I expect "test" to appear for each print statement (i. e. four times here). I tried to go everywhere on the Internet, I tried various tutorials, I tried to copy various examples, to follow various videos, I just don't succeed in fixing this issue.
Note that this piece of code is embedded into a function called saveGame, which is used in a pygame loop.
Thanks in advance! All the best!
Your code works.
The window is not drawn on the screen until you call mainloop(), so printing M.filename before that point prints an empty string (the initialization value). The mainloop() blocks until the window closes, after which 3 print statements successfully print the value that the user entered into the box.
You may be interested in the easygui module, which does exactly what your program does except you don't have to make it yourself.
Ok, as other posters told, the above code works in a vacuum. It did not work as embedded in my program because I initialized a duplicate tk() before calling my function and initialize it again. I removed this duplicate and it worked.
Related
I'm writing my first GUI program today using Tkinter and I have stumbled onto a problem. I am trying to make a game that starts with an introduction window that closes after you press a button, then opens a new window where you can choose one of two modes. Unfortunately, I just can't get it running. It looks a little something like this.
#These are the functions that I defined to make it work
def start():
root.destroy()
def Rules_mode_1():
root.destroy
rules1 = Tk()
understood1 = Button(rules1, text="I understood", command="Start_game_mode_1")
understood.pack()
rules1.mainloop
# I haven't added rules 2 yet cause I couldn't get it to work with rules 1 so I haven't even #bothered but it would be the same code just switching the 1 for a 2. But really it isn't even
#necessary to have 2 different rule functions because the rules are the same but I couldn't think
#of another way to go about it. if you have an idea let me know
def Start_game_mode_1():
rules1.destroy #<----- THIS IS WHERE THE PROBLEM LIES. JUST DOESN'T RUN
gamemode1 = Tk()
#Here I would have the game
gamemode1.mainloop()
#now same here don't have gamemode 2 yet cause it just doesn't work yet
#This is where it really starts
root = Tk()
startbutton = Button(root, text="Start", command=start)
startbutton.pack
root.mainloop
root = Tk()
def mode():
mode1 = Button(root, command=Rules_mode_1)
mode1.pack
mode2 = #Buttonblablabla
mode()
root.mainloop()
Now I've been trying around for hours, trying to give the mainloops different names. For example giving the
rules1.mainloop
#the name
root.mainloop
but that obviously didn't work. I tried it with dozens of helper function and with the lambda expression and did hours of research but just can't seem to fix it. Does anybody have any ideas? Please be respectful and keep in mind it's my first time using Tkinter.
Thank you for your help!
After the comments didn't really help me I just tried things out for hours and in case anybody ever is having a a similar problem and reads this: The rules1 variable is inside a function, and therefore only local, which means it can't be destroyed in another function. I fixed it by making it a global, like:
def Rules_mode_1():
root.destroy
global rules1
rules1 = Tk()
understood1 = Button(rules1, text="I understood", command="Start_game_mode_1")
understood.pack()
rules1.mainloop
After that I could destroy the mainloop in the next function.
New to GUI. Not quite getting there. I used page and get can get buttons to do something (click on a button and get a response). With Combobox, I can't pass a value. Searched here, tried many things, watched a few hours of youtube tutorials.
What am I doing wrong below? This is the code page generates (basically) then I added what I think I need to do to use the Combobox.
I am just trying to have 1,2,3 in a combo box and print out the value that is chosen. Once I figure that out I think I can actually make a simple GUI that passes variables I can then program what I want to do with these variables being selected.
class New_Toplevel_1:
def __init__(self, top):
self.box_value = StringVar()
self.TCombobox1 = ttk.Combobox(textvariable=self.box_value)
self.TCombobox1.place(relx=0.52, rely=0.38, relheight=0.05, relwidth=0.24)
self.TCombobox1['values']=['1','2','3']
self.TCombobox1.configure(background="#ffff80")
self.TCombobox1.configure(takefocus="")
self.TCombobox1.bind('<<ComboboxSelected>>',func=select_combobox)
def select_combobox(self,top=None):
print 'test combo ' # this prints so the bind works
self.value_of_combo = self.ttk.Combobox.get() # this plus many other attempts does not work
It's hard to know what you're actually asking about, since there is more than one thing wrong with your code. Since you say the print statement is working, I'm assuming the only problem you have with your actual code is with the last line.
To get the value of the combobox, get the value of the associated variable:
self.value_of_combo = self.box_value.get()
Here's a working version where I fixed the other things that were wrong with the program:
from tkinter import *
from tkinter import ttk
class New_Toplevel_1:
def __init__(self, top):
self.box_value = StringVar()
self.TCombobox1 = ttk.Combobox(textvariable=self.box_value)
self.TCombobox1.place(relx=0.52, rely=0.38, relheight=0.05, relwidth=0.24)
self.TCombobox1['values']=['1','2','3']
self.TCombobox1.configure(background="#ffff80")
self.TCombobox1.configure(takefocus="")
self.TCombobox1.bind('<<ComboboxSelected>>',func=self.select_combobox)
def select_combobox(self,top=None):
print('test combo ') # this prints so the bind works
self.value_of_combo = self.box_value.get()
print(self.value_of_combo)
root = Tk()
top = New_Toplevel_1(root)
root.mainloop()
Note: I strongly advise you not to start with place. You should try to learn pack and place first. I know place seems easier, but to get the most responsive and flexible GUI you should leverage the power of pack and grid.
So, essentially what is going on is I made a password manager that had a password generation part to it, I moved it to a windowed Tkinter program for ease of use. I got everything down except for the check box, so at first when the function was called it would give me the error that alphabet had empty length so I set alphabet equal to the list with special characters. After that I tried them with while loops, same result. (this whole code is a function inside the program that only gets ran when a button is pressed) I know I could probably fix this issue with the init but I was hoping if anyone knew an easier way without rewriting too much. Here is the edit to make the code simplified. I used it with a while loop, and got the same result as the if statement. I get the error that a is not defined in this situation.
from tkinter import *
import random
def cbox_var():
while cbox_1 == True:
a = 10
while cbox_1 == False:
a = 20
print(a)
main = Tk()
cbox_1 = Checkbutton(main, text="yes or no")
cbox_1.pack()
testbutton = Button(main,text="Test", command=cbox_var)
testbutton.pack()
main.mainloop()
To get the value of a checkbutton you must assign one of the special tkinter variables to it. You can then get the value by calling the get method on the variable.
Example:
import tkinter as tk
def cbox_var():
checked = cbox_variable.get()
print("Checked?", checked)
main = tk.Tk()
cbox_variable = tk.BooleanVar()
cbox_1 = tk.Checkbutton(main, variable=cbox_variable, text="yes or no")
cbox_1.pack()
testbutton = tk.Button(main,text="Test", command=cbox_var)
testbutton.pack()
main.mainloop()
I have this function inside one of my python scripts which throws up a Tkinter simple dialog screen to ask for some simple user-input. The function works. However, there are 2 problems with it.
It opens up two windows, while all I need is one. But if I remove the master = Tk() I get the error:
AttributeError: 'NoneType' object has no attribute 'winfo_viewable'
It would be nice to at one point figure that one out, but my main problem however is the second one:
Whenever the simple dialog screen turns up, I have to click it first before it gets activated, which is annoying. To fix it I tried the solutions offered here and here but they do not work. The first link didn't do anything for me at all, the second link helped me to lift the master.Tk() window to the front, but that is not what I need. I need the simple dialog window to become the topmost window and I need it to be auto-activated so that when I run my code and the screen pops-up I can automatically type in it without having to click on it first.
Any help would be greatly appreciated!
My code:
def getUser():
master = Tk()
newList2=str(newList).replace(", ","\n")
for ch in ['[',']',"'"]:
if ch in newList2:
newList5=newList2.replace(ch,"")
userNr=simpledialog.askinteger("Enter user number", newList2)
chosenUsernr= userNr - 1
global chosenUsernrdef
chosenUsernrdef = chosenUsernr
master.destroy()
I don't think there is a way to lift/give focus to it but askinteger is merely a combination of couple widgets so you can easily recreate it yourself.
import tkinter as tk
from tkinter import messagebox
class CustomAskInteger(tk.Tk):
def __init__(self, numbers):
tk.Tk.__init__(self)
self.value = None
self.label = tk.Label(self, text=", ".join(map(str, numbers))).pack(fill="both", expand=True)
self.entry = tk.Entry(self)
self.button = tk.Button(self, text="Ok", command=self.get_number)
self.entry.pack()
self.button.pack()
def get_number(self):
"""
You can customize these error handlings as you like to
"""
if self.entry.get():
try:
int(self.entry.get())
self.value = self.entry.get()
self.destroy()
except ValueError:
messagebox.showwarning("Illegal Value", "Not an integer.\nPlease try again.")
else:
messagebox.showwarning("Illegal Value", "Not an integer.\nPlease try again.")
To use this in your code, you can do
def getUser():
newList2=str(newList).replace(", ","\n")
askInteger = CustomAskInteger("Enter user number", newList2)
#since it is a Tk() instance, you can do lift/focus/grab_set etc. on this
askInteger.lift()
askInteger.mainloop()
userNr = askInteger.value
First, credits to Lafexlos for showing a solution of how to apply .lift() and similar commands on a Tkinter simpledialog.askinteger() window by recreating such a window as a Tk() instance.
For those however looking how to automatically activate a Tk-window (so you do not have to click on it before being able to type in it), there appear to be multiple options.
The most common solution seems to be to use .focus() or .force_focus() as seen implemented here and here. However over here it seems those options may not work on (at least some versions of) Windows OS. This question shows a possible solution for those systems. Also, the previous solutions appear not to work on multiple versions of OS X. Based on the solution offered here, using Apple's osascript, I was able to solve my problem.
The working code eventually looks like this:
def getUser():
master = Tk()
newList2=str(newList).replace(", ","\n")
for ch in ['[',']',"'"]:
if ch in newList2:
newList2=newList2.replace(ch,"")
cmd = """osascript -e 'tell app "Finder" to set frontmost of process "Python" to true'"""
def stupidtrick():
os.system(cmd)
master.withdraw()
userNr=simpledialog.askinteger("Enter user number", newList2)
global chosenUsernrdef
chosenUsernr= userNr - 1
chosenUsernrdef = chosenUsernr
stupidtrick()
master.destroy()
Simplified / general solution:
import os
from tkinter import Tk
from tkinter import simpledialog
def get_user():
root = Tk()
cmd = """osascript -e 'tell app "Finder" to set frontmost of process "Python" to true'"""
def stupid_trick():
os.system(cmd)
root.withdraw()
new_window=simpledialog.askinteger("Title of window", "Text to show above entry field")
stupid_trick()
root.destroy()
get_user()
EDIT: Now I am figuring out what to look for the solution appears to be found already by multiple posts. For those on OS X wanting to activate a specific Tkinter window when multiple instances of Tkinter and/or python are running simultaneously, you might want to look here.
I have some pretty simple code right now that I am having issues with.
root = Tk()
label1 = Label(root, text ="Enter String:")
userInputString = Entry(root)
label1.pack()
userInputString.pack()
submit = Button(root,text = "Submit", command = root.destroy)
submit.pack(side =BOTTOM)
root.mainloop()
print(userInputString)
When I run the code everything operates as I would expect except
print(userInputString)
for an input asdf in the Entry print will return something like 0.9355325
But it will never be the same value back to back always random.
I am using python 3.5 and Eclipse Neon on a Windows 7 Machine.
Ultimately the goal is to accept a string from the user in the box that pops up and then be able to use that value as string later on. For example, it might be a file path that needs to be modified or opened.
Is Entry not the correct widget I should be using for this? Is there something inherently wrong with the code here? I am new to python and don't have a lot of strong programming experience so I am not even certain that this is set up right to receive a string.
Thanks in advance if anyone has any ideas.
There are two things wrong with your print statement. First, you print the widget, not the text in the widget. print(widget) prints str(widget), which is the tk pathname of the widget. The '.' represents the root window. The integer that follows is a number that tkinter assigned as the name of the widget. In current 3.6, it would instead be 'entry', so you would see ".entry".
Second, you try to print the widget text after you destroy the widget. After root.destroy, the python tkinter wrapper still exists, but the tk widget that it wrapped is gone. The following works on 3.6, Win10.
import tkinter as tk
root = tk.Tk()
label = tk.Label(root, text="Enter String:")
entry = tk.Entry(root)
def print_entry(event=None):
print(entry.get())
entry.bind('<Key-Return>', print_entry)
entry.focus_set()
submit = tk.Button(root, text="Submit", command=print_entry)
label.pack()
entry.pack()
submit.pack()
root.mainloop()
Bonus 1: I set the focus to the entry box so one can start typing without tabbing to the box or clicking on it.
Bonus 2: I bound the key to the submit function so one can submit without using the mouse. Note that the command then requires an 'event' parameter, but it must default to None to use it with the button.
The NMT Reference, which I use constantly, is fairly complete and mostly correct.