Line numbers in Text widget

[rfresh737]

I added some code to improve it and noted some issues:

(1) Here is a link to a test file with 200 lines, with each line numbered.

line_test.txt file

(2) when the app starts up, the text widget gets the focus right away so the line numbers are there from the start.

(3) I added a binding so you can mouse wheel (scroll) down in the text file. However, doing so causes the line numbers to get out of sync. I suspect it's because one mouse wheel click inputs more than one line down movement like the keyboard down arrow does: one line down to one key press. The wheel is multiple lines down to one wheel click. I'm not sure how to fix this, but if you can point me in the right area to look at, I might be able to figure it out. Mouse wheel clicks to how many lines move up or down is configurable, so I don't know if that plays into a fix or not. But I'll have a look and see what I can come up with if you can point me in the right direction.

(4) The PgDn/PgUp keys have a similar effect, but not for all PgDn clicks for some reason. I can hit PgDn a few times and notice the Text widget lines are out of sync with the line numbers as well as not horizontally aligned. If you can tell me what controls the horizontal alignment, I probably can make an adjustment and fix that.

Thank you again...

from tkinter import *

class LineNumbers(Text):
    def __init__(self, master, text_widget, **kwargs):
        super().__init__(master, **kwargs)

        self.text_widget = text_widget
        self.text_widget.bind('<KeyRelease>', self.on_key_release)
        self.text_widget.bind('<FocusIn>', self.on_key_release)
        self.text_widget.bind('<MouseWheel>', self.on_key_release)

        self.insert(1.0, '1')
        self.configure(state='disabled')

    def on_key_release(self, event=None):
        p, q = self.text_widget.index("@0,0").split('.')
        p = int(p)
        final_index = str(self.text_widget.index(END))
        num_of_lines = final_index.split('.')[0]
        line_numbers_string = "\n".join(str(p + no) for no in range(int(num_of_lines)))
        width = len(str(num_of_lines))

        self.configure(state='normal', width=width)
        self.delete(1.0, END)
        self.insert(1.0, line_numbers_string)
        self.configure(state='disabled')


if __name__ == '__main__':
    win = Tk()
    win.title("Line Numbers Test")
    win.geometry("800x600+1000+300")

    txt = Text(win)
    ln = LineNumbers(win, txt, width=2)

    f = open("line_test.txt", 'r')
    lines = f.readlines()
    for line in lines:
        txt.insert(END, line)
    f.close()

    ln.pack(side=LEFT, fill=BOTH)
    txt.pack(expand=True, fill=BOTH)
    txt.focus()
    win.mainloop()