Develop Reference

Why won't Tkinter executable capture key combinations?

I'm building an tkinter app on Python 3.7 and creating an .exe with Pyinstaller 3.5 in Windoows 10. When running the code from the IDE, all intended keyboard commands work as expected. However, in the executable, key combinations do not work while single key presses are fine.
Here is some test code that demonstrates the problem:
import tkinter as tk
root = tk.Tk()
txt = tk.StringVar()
lbl = tk.Label(root, textvariable=txt)
def key_handle(event):
global txt
txt.set(event.keysym)
def kc_handle(event):
tk.messagebox.showinfo('Key Combo', 'Key Combo pressed')
root.bind('<Key>', key_handle)
root.bind('<Alt-b>', kc_handle)
lbl.pack()
root.mainloop()
Pyinstaller is then invoked as pyinstaller -w -F key_test.py.
One thing I do know is that the order of the binds doesn't seem to make a difference. How do I get key combinations working in the executable?

IDLE is built using tkinter and it could import all needed modules for own use and your code could work correctly but when you run it without IDLE then you have to import all modules which you use in code. In your example it will be
import tk.messagebox
BTW: Often similar problem is with mainloop(). IDLE aready runs mainloop() so code may work without own mainloop(). But normally (without IDLE) it needs to use mainloop(). It is good to check code in terminal/console/cmd.exe to see if it gives any errors.

Tkinter askopenfilename() won't open

I have a selection of excel data that I am analyzing, and have just recently added the ability for the user to open the file explorer and locate the file visually, as opposed to entering the file location on the command line. I found this question (and answer) to make the window appear, which worked for a while.
I am still using the command line for everything except locating the file. Currently, this is a skeleton of what I have to open the window (nearly identical to the answer of the question linked above)
Tk().withdraw()
data_file_path = askopenfilename()
# other code with prompts, mostly print statements
Tk().withdraw()
drug_library_path = askopenfilename()
Once the code reaches the first two lines of code, the command line just sits with a blinking cursor, like it's waiting for input (my guess, for askopenfilename() to return a file location), but nothing happens. I can't ctrl+C to get out of the program, either.
I have found this question, which is close to what I'm looking for, but I'm on Windows, not Mac, and I can't even get the window to open -- most questions I see talk about not being able to close the window.
Thanks for any help!
Note: At this point in the program, no data from excel has been loaded. This is one of the first lines that is ran.

Try easygui instead. It's also built on tkinter, but unlike filedialog it's made to run without a full GUI.
Since you are using Windows, use this command in the command line (not in python) to install easygui:
py -m pip install easygui
then try this code:
import easygui
data_file_path = easygui.fileopenbox()
# other code with prompts, mostly print statements
drug_library_path = easygui.fileopenbox()

If you want to use an internal module, you can import tkFileDialog, and call:
filename = tkFileDialog.askopenfilename(title="Open Filename",filetypes=(("TXT Files","*.txt"),("All Files","*.*")))
I use this in many projects, you can add arguments such as initialdir, and you can specify allowable filetypes!

I had the same problem, but I found that the issue was that I was getting input with input() before I called askopenfilename() or fileopenbox().
from tkinter import Tk
from tkinter.filedialog import askopenfilename
var = input()
Tk().withdraw()
filepath = askopenfilename()
I simply switched the positions of askopenfilename() (or fileopenbox()) and input(), and it worked as usual.
Tk().withdraw()
filepath = askopenfilename()
var = input()

How to use idlelib.PyShell to embed an interpreter in a tkinter program?

I need to embed an interative python interpreter into my tkinter program. Could anyone help me out as to how to integrate it?
I have already looked at the main() function, but it's way to complex for my needs, but I can't seem to reduce it without breaking it.

Some details of what you must do may depend on what you want to do with IDLE's Shell once you have it running. I would like to know more about that. But let us start simple and make the minimum changes to pyshell.main needed to make it run with other code.
Note that in 3.6, which I use below, PyShell.py is renamed pyshell.py. Also note that everything here amounts to using IDLE's private internals and is 'use at your own risk'.
I presume you want to run Shell in the same process (and thread) as your tkinter code. Change the signature to
def main(tkroot=None):
Change root creation (find # setup root) to
if not tkroot:
root = Tk(className="Idle")
root.withdraw()
else:
root = tkroot
In current 3.6, there are a couple more lines to be indented under if not tkroot:
if use_subprocess and not testing:
NoDefaultRoot()
Guard mainloop and destroy (at the end) with
if not tkroot:
while flist.inversedict: # keep IDLE running while files are open.
root.mainloop()
root.destroy()
# else leave mainloop and destroy to caller of main
The above adds 'dependency injection' of a root window to the function. I might add it in 3.6 to make testing (an example of 'other code') easier.
The follow tkinter program now runs, displaying the both the root window and an IDLE shell.
from tkinter import *
from idlelib import pyshell
root = Tk()
Label(root, text='Root id is '+str(id(root))).pack()
root.update()
def later():
pyshell.main(tkroot=root)
Label(root, text='Use_subprocess = '+str(pyshell.use_subprocess)).pack()
root.after(0, later)
root.mainloop()
You should be able to call pyshell.main whenever you want.

graphics.py GraphWin automatically closing

I'm new to Python and trying to learn graphics with John Zelle's graphics.py. I'm writing the Python scripts in MacVim and executing from the terminal (Mac OS 10.9.2) on Python 3. If I try to open a new window with GraphWin() the window opens briefly but then immediately closes.
Ex:
from graphics import *
win = GraphWin("circle",500,500)
c = Circle(point(100,100),30)
c.draw(win)
GUI elements with TkInter work just fine.
Any ideas why this might be happening?
Thanks!

If the statements you've shown in your question were entered as a script, and you just ran the script, then the problem is that the window is closed implicitly when the script ends. You will see in the very first example from the documentation (which also appears in the source code for graphics.py itself):
from graphics import *
def main():
win = GraphWin("My Circle", 100, 100)
c = Circle(Point(50,50), 10)
c.draw(win)
win.getMouse() # Pause to view result
win.close()
main()
Notice that the author has specifically included a statement to pause before closing the window.
If, instead of a script, you just type the statements in one by one at an interactive Python prompt, then as long as that Python prompt is open, the graphics window stays open (until you explicitly close it, or close the Python session).

Python Tkinter not working in a .py file

My problem is that my python code is not working when I run it as a .py file. Here is the code:
import tkinter
tk=tkinter.Tk()
canvas=tkinter.Canvas(tk, width=500, height=500)
canvas.pack()
There is more code to it than that, but that is the relevant stuff. It works fine when I use the python shell or type it directly into the python console, but when I run it as a .py file, it seems to skip this code and go on to the rest, without displaying a canvas. I am using windows, but I am not sure what version of python I'm using.
I was also using
from * import tkinter
before, with relevant changes to the code and i changed it to try and help fix it. It didn't work :(

You are missing the eventloop at the end:
import tkinter
tk=tkinter.Tk()
canvas=tkinter.Canvas(tk, width=500, height=500)
canvas.pack()
# Enter into eventloop <- this will keep
# running your application, until you exit
tk.mainloop()
Only a personal recommendation: don't use tk as a variable name, use app or root or even win/window