tkinter wraplength units is pixels?

Question

Re: wraplength for tkinter.Label, from the NM Tech docs by John Shipman: "You can limit the number of characters in each line by setting this option to the desired number. The default value, 0, means that lines will be broken only at newlines." Other sources agree that the units for wraplength are characters.

The code below seems to be breaking the line as if the units of wraplength were pixels, not characters. If I set wraplength to 10, for example, the label displays a column of text one or two characters wide. If I set wraplength to 20, the lines are 3 or 4 characters long.

In my application, the user will be creating his own simple widgets for custom forms, and it would be better if the wraplength option used character count for units instead of whatever it is doing. Since the NMTech docs are for Tkinter 8.5, but 8.6 is what comes with my Python 3.5, maybe that explains the difference, but I don't see docs for 8.6.

But ideally, lines should wrap at the nearest space between words with wraplength just used as a maximum line length. So if the user has to type in his own \n anyway, wraplength seems useless to me.

Summary: in a GUI for users who will be inputing option values for their own simple widgets, 1) is there a way to get Tkinter to accept characters for wraplength units and 2) can I get the line to break at the nearest space short of the wraplength with wraplength used as a maximum line length only, instead of an absolute line length?

Thanks for any solutions or suggestions.

import tkinter as tk

root = tk.Tk()

sib = tk.Label(root, text='Give em hell Harry', wraplength=10)
sib.grid()

root.mainloop()

Answer 1

Is there a way to get Tkinter to accept characters for wraplength units

No, there is not. If you need wrapping to happen at word boundaries you can use a text widget rather than a label.

Unless specified otherwise, the units are in pixels. From the canonical tk documentation:

wraplength For widgets that can perform word-wrapping, this option specifies the maximum line length. Lines that would exceed this length are wrapped onto the next line, so that no line is longer than the specified length. The value may be specified in any of the standard forms for screen distances. If this value is less than or equal to 0 then no wrapping is done: lines will break only at newline characters in the text.

In the above text, "any of the standard forms for screen distances" refers to the fact that you can use a suffix to specify the distance in printers points (eg: "72p"), centimeters (eg: "2.54c"), millimeters (eg: "1000m"), or inches (eg: "1i")

Answer 2

This answer is two years later, but if anyone that sees it and needs to wrap text in a label based on characters or words, you could use the textwrap module. It's very useful if you don't want words to get cut-off between lines but still want to keep them in a label widget.