tk messagebox import confusion - python

I'm just beginning to learn tkinter at the moment, and when importing messagebox I found that I must not really understand import statements.
The thing that confuses me is that:
import tkinter as tk
def text_box():
if tk.messagebox.askokcancel("Quit", "Never Mind"):
root.destroy()
root = tk.Tk()
button = tk.Button(root, text="Press the button", command=text_box)
button.pack()
root.mainloop()
compiles fine, but pressing the button gives the error 'module' object has no attribute 'messagebox', while the code:
import tkinter as tk
from tkinter import messagebox
...
if messagebox.askokcancel("Quit", "Never Mind"):
...
...works without a hitch.
I get a similar error if I import with from tkinter import *.
The help for tkinter shows messagebox in the list of PACKAGE CONTENTS, but I just can't load it in the normal way.
So my question is, why...and what is it about importing that I don't understand?
Just thought I should mention—the code only works in Python 3, and in Python 2.x messagebox is called tkMessageBox and is not defined in tkinter.


tkinter.messagebox is a module, not a class.
As it isn't imported in tkinter.__init__.py, you explicitly have to import it before you can use it.
import tkinter
tkinter.messagebox # would raise an ImportError
from tkinter import messagebox
tkinter.messagebox # now it's available eiter as `messagebox` or `tkinter.messagebox`


try this
import sys
from tkinter import *
... and your code

Related

Why tkinter filedialog is looking different after using a pyglet window?

I have used a tkinter.filedialog with the pyglet library. But an old file explorer pops up when I open that filedialog. Normally it opens the native/modern file explorer of windows, but it is showing this behavior after importing the pyglet module. Any solution to get back the new filedialog?
Here is a basic code to reproduce the issue:
from tkinter import Tk, Button, filedialog
import pyglet #Try commenting this import to test the filedialog
root= Tk()
root.geometry("200x100")
window = pyglet.window.Window(20, 20, "Pyglet_window") #Pyglet window
def open_file():
file=filedialog.askopenfilename()
btn= Button(root, width=10,bg="#FFFFFF",fg="black", text="Open File",command=open_file)
btn.grid(padx=50,pady=20)
root.mainloop()
My results:

new window title in tkinter

I'm new to tkinter in python and am not able to figure out what the syntax below does exactly.
oldtitle=window.newtitle()
Removing this line from the code doesn't makes any difference to the output.
from tkinter import *
from tkinter import ttk
root=Tk()
root.title('to')
main=Toplevel(root)
tk=main.title()#<---this line
main.title('hello world')
mainloop()

What the line tk=main.title() does is to get the title of main.
Here is a demo using your own code:
from tkinter import *
from tkinter import ttk
root=Tk()
root.title('to')
main=Toplevel(root)
main.title('hello world')
tk=main.title() # Note I moved this line to here
print(tk) # This will print 'hello world'
mainloop()
The line print(tk) will print the title of main which is hello world.
If you want to set a different title then use this synatax instead: tk = main.title('Some new title') (or simply main.title('Some new title') if you do not need to save the title string into an other variable):
from tkinter import *
from tkinter import ttk
root=Tk()
root.title('to')
main=Toplevel(root)
main.title('hello world')
tk=main.title('Some new title') # or simply: main.title('Some new title')
mainloop()
Output:
Note: avoid using tk as your personal variable name because the recommended way to import tkinter is: import tkinter as tk

Python: import not importing messagebox

from tkinter import *
from tkinter import messagebox
root = Tk()
messagebox.showinfo("Hello world", "you are the best")
root.mainloop()
Why do I have to have to import messagebox explicitly when I am import all using *

messagebox is a submodule of the tkinter package.
The wildcard import syntax doesn't import submodules, only the names that are defined in the tkinter package itself.
Therefore you need to import the messagebox submodule explicitly.
References
https://docs.python.org/3/library/tkinter.html#tkinter-modules
https://docs.python.org/3/reference/simple_stmts.html#the-import-statement
Relevant tkinter sources
https://github.com/python/cpython/blob/3.6/Lib/tkinter/__init__.py
https://github.com/python/cpython/blob/3.6/Lib/tkinter/messagebox.py

Tkinter not working in cmd (working in IDLE)

I am trying to display a directory selection dialog box (for getting a path and then for saving downloaded stuff).The code runs fine in IDLE but when i try to run it in CMD i get this error
NameError: name 'Tk' is not defined
I am using tkinter for gui.
Code Snippet
from tkinter import filedialog
root = Tk()
root.withdraw()
filename = filedialog.askdirectory()
Using Python 3.4.3. Any help/suggestions?

The statement from tkinter import filedialog only imports the filedialog module from tkinter. If you want the usual Tkinter stuff, you have to import that too. I'd recommend import tkinter as tk and then referring to it with e.g. root = tk.Tk() so you don't just dump everything into the global namespace. Or, if you really just want the root object, use from tkinter import Tk.
from tkinter import Tk
from tkinter import filedialog
root = Tk()
root.withdraw()
filename = filedialog.askdirectory()

Python QtGui Calendar Widget Call button

I am using a calendar widget for Python. And I need to call the widget when a button is clicked.
The situation is that I cannot find what is the method in the calendar class that displays the widget itself.
The calendar class was taken from here:
http://www.eurion.net/python-snippets/snippet/Calendar_Date%20picker.html
Here are my imports:
from tkinter import *
from tkinter import ttk
import tkinter.messagebox
import time
import requests #needs to be installed
import pymysql #needs to be installed
import csv
import win32com.client #needs to be installed
from calendar import Calendar
import datetime
Here is the button creation:
# Calendar Buttons
calBut=ttk.Button(f2, width=4, text="Cal", command=Calendar.what_method?).grid(column=3,row=1, sticky=W)
As far as I know, I can just set the command of the button to call the widget display method located in the calendar class.
How to get the method that displays the calendar widget each time my button is clicked? None of the ones showing are displaying the widget.
Using Python 3.3.5
Spider
WinPython 3.3.5
**EDIT**
The program has tabs and the f2 indicates the tab where the button will be.
from tkinter import *
from tkinter import ttk
import tkinter.messagebox
import time
import requests #needs to be installed
import pymysql #needs to be installed
import csv
import win32com.client #needs to be installed
import datetime
from calendar import Calendar
import calendar
#################################
# Create Button Click Calendar
def callback():
root2=Toplevel(f2)
ttkcal = Calendar(root2,firstweekday=calendar.SUNDAY)
ttkcal.pack(expand=1, fill='both')
root2.update()
root2.minsize(root2.winfo_reqwidth(), root2.winfo_reqheight())
# Calendar Buttons
b=ttk.Button(f2, width=4, text="Cal", command=callback).grid(column=3,row=1, sticky=W)
When I press the button, it opens the calendar window, but it is empty. And the console gives me error:
TypeError: __init__() got multiple values for argument 'firstweekday
Thank you

Not so easy. The problem is that you mix the two GUI libraries. Therefore it is necessary two main event loops (at least): one for Tkinter code and one for PyQt code.
One way to do what you want - using subprocess and threading modules to run calendar.py in different thread. Example:
from tkinter import *
from tkinter import ttk
import subprocess
import threading
master = Tk()
def callback():
subprocess.call('python calendar.py')
b=ttk.Button(master, width=4, text="Cal", command=lambda:threading.Thread(target=callback).start()).grid(column=3,row=1, sticky=W)
mainloop()
Another way - creating Qt main event loop inside callback function (dirty solution):
from tkinter import *
from tkinter import ttk
from calendar import Calendar
import sys
from PyQt4 import QtGui
master = Tk()
def callback():
app = QtGui.QApplication(sys.argv)
gui = Calendar()
gui.show()
app.exec_()
b=ttk.Button(master, width=4, text="Cal", command=callback).grid(column=3,row=1, sticky=W)
mainloop()
EDIT: How to call widget.
First of all, look at this answer, and modify your ttkcalendar.py as kalgasnik suggested. Then try this:
from tkinter import *
from tkinter import ttk
from ttkcalendar import Calendar
import calendar
master = Tk()
def callback():
root2=Toplevel(master)
ttkcal = Calendar(root2,firstweekday=calendar.SUNDAY)
ttkcal.pack(expand=1, fill='both')
root2.update()
root2.minsize(root2.winfo_reqwidth(), root2.winfo_reqheight())
b=ttk.Button(master, width=4, text="Cal", command=callback).grid(column=3,row=1, sticky=W)
mainloop()
EDIT 2. Solving the problems
Ok, it seems I found all problems.
Actually, you import twice the same module - standard calendar module:
from calendar import Calendar
import calendar
But you do not import the class Calendar from ttkcalendar module (Do not forget to change it as described
here).
So, import should look like this:
import ttkcalendar
import calendar
Creating calendar (I changed the code a bit for clarity):
ttkcal = ttkcalendar.Calendar(root2,firstweekday=calendar.SUNDAY)
In your code, the main window is initialized twice:
line 15: master = Tk()
line 960: root = Tk()
You need to remove the first initialization.
You mix pack() and grid() in the same master window. According the docs, it is a bad idea:
Warning: Never mix grid and pack in the same master window. Tkinter
will happily spend the rest of your lifetime trying to negotiate a
solution that both managers are happy with. Instead of waiting, kill
the application, and take another look at your code. A common mistake
is to use the wrong parent for some of the widgets.
So, instead nb.pack(fill='both', expand='yes') you have to write something like this
nb.grid(column=0, row=0, sticky=(W, E))
Finally, here are links to the fixed code:
ttkcalendar.py (already modified, ready to use): https://gist.github.com/anonymous/5e0d973f57e185572df2
Your script with described modifications:
https://gist.github.com/anonymous/65cb808dc64e414c0c12

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