Tkinter: I can't highlight text in text widget

Question

So I made a text editor using tkinter and I used tag_config to highlight the syntax.

CODE

#Importing modules
from tkinter import *

#Main Window
Window = Tk()
Window.minsize(400, 550)

##Main Script
#Defs


#Main frame
main = Frame(Window)

#Main text widget
text = Text(main, bd=0, highlightthickness=0, borderwidth=0, bg="#323232", fg="white")

#Configs
text.config(width=55, height=35)
main.config(width=55, height=35)

#Tag config for coloring syntax
text.tag_configure("import", foreground="yellow")
Window.update()

#Packs and places
#main.place(anchor="c", rely=.5, relx=.5)
main.pack(expand=True, fill=BOTH, side="right")

text.pack(expand=True, fill=BOTH)

#Update window
Window.update()

#Window.mainloop()
Window.mainloop()

PROBLEM
The tag_configure is not working in line 23
text.tag_configure("import", foreground="yellow")

QUESTION
Is there a way to fix that? or Is there any way to highlighting text in tkinter?

EDIT
I add

def check_syntax(event):
    text.tag_add('import', 1.0, END)       

text.bind("<Return>", check_syntax)

on the code but there are 1 problem, when i run the code and type import tkinter in the text widget for test and press enter the "tkinter" is highlighted too
How to fix that?

Do you have to call use `tag_add(tagname, startindex[,endindex] ...)` also? And then `tag_delete(tagname)` or tag_remove(tagname, startindex[,endindex] ...)` to remove the tag. — TheLazyScripter, Aug 13 '20 at 05:40

score 0 · Answer 1 · answered Aug 13 '20 at 05:43

I believe the reason is that you need to actually add a tag first using the tag_add function. You should read this other question with a similar problem. I tried out the code myself and it works. (You'll have to press enter after completing a line)

How to use tkinter tag_config? Python 3.7.3

score 0 · Answer 2 · answered Aug 13 '20 at 14:20

tag_configure only configures a tag, it doesn't apply the tag to a range of text. To use the tag you need to call tag_add and give it a start and end index. That, or add the tag when calling insert.

For example, this shows how to insert some text, and then apply highlighting to a few characters:

text.insert("end", "import foo\nimport bar\n")
text.tag_add("import", "1.0", "1.6")
text.tag_add("import", "2.0", "2.6")

Tkinter: I can't highlight text in text widget

2 Answers2