CODEWITHSUNDEEP
python-2.7tkinterpython-import
JDM
JDM

Reputation: 1804

Cannot import Tkinter font object from module

I've got a feeling this will end in a facepalm, but I just can't puzzle out why this import x from y scenario isn't working for me. As a starting point, take the following module main.py:

import Tkinter as tk
import tkFont
__metaclass__ = type
#Create widgets
root = tk.Tk()
fntPlainText = tkFont.Font(family='Courier New',size=10)
lblDisplay = tk.Label(root, relief=tk.SUNKEN,
                      font=fntPlainText,
                      width=30,height=5,
                      text='This is a test!')
#Do layout
lblDisplay.grid(padx=5,pady=5)
#Begin app
tk.mainloop()

This runs normally and puts up a small label with the expected content:

enter image description here

So now I want to move the definition of this Font object to a separate module, so I can share it among multiple applications. My updated code modules are fonts1.py:

import Tkinter as tk
import tkFont
__metaclass__ = type
fntPlainText = tkFont.Font(family='Courier New',size=10)

...and main1.py:

import Tkinter as tk
from fonts1 import fntPlainText
__metaclass__ = type

#Create widgets
root = tk.Tk()
lblDisplay = tk.Label(root, relief=tk.SUNKEN,
                      font=fntPlainText,
                      width=30,height=5,
                      text='This is a test!')
#Do layout
lblDisplay.grid(padx=5,pady=5)
#Begin app
tk.mainloop()

But when I run main1.py, I get a traceback:

Traceback (most recent call last):
  File "G:\Python\experiments\investigations\tk\main1.py", line 2, in <module>
    from fonts1 import fntPlainText
  File "G:\Python\experiments\investigations\tk\fonts1.py", line 5, in <module>
    fntPlainText = tkFont.Font(family='Courier New',size=10)
  File "C:\Python27\lib\lib-tk\tkFont.py", line 89, in __init__
    tk.call("font", "create", self.name, *font)
AttributeError: 'NoneType' object has no attribute 'call'

From Googling and experimenting, I found enough to know that something's going wrong with the assignment of fntPlainText, but (again) I can't figure out what it is. The biggest puzzle of the whole situation is that when I pare down fonts1.py to simply define fntPlainText as a tuple--

Modified fonts1.py:

fntPlainText = ('Courier New',10)

Running main1.py now completes normally and paints the same window as main.py.

If it matters, the environment is Python 2.7.x running on Windows 7.

Upvotes: 1

Views: 2515

Answers (1)

Matt
Matt

Reputation: 359

You need to create a root window (tk.Tk()) before creating the font. If you move your

from fonts1 import fntPlainText

below the tk.Tk() call it should work as you expect.

Upvotes: 2

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