Python: Replace last line in text file

I have been struggling with python script to replace last line in a text file.

I have tried several Answers example:

how-do-i-modify-the-last-line-of-a-file

efficient-way-to-edit-the-last-line-of-a-text-file-in-python

None of that worked

I am using Python 3.10

All I need is to python overwrite last line of text file example

line1
line2
line3
lastline

to be overwritten to

line1
line2
line3
overwritten_lastline

Could someone please help me?

>Solution :

file = open('example.txt','r')
lines = file.readlines()[:-1]
lines.append("YOUR NEW LINE")
file.close()
file = open('example.txt','w')
file.writelines(lines)

It cannot be more simpler than replacing one by one all the lines. Here’s my answer that has just worked for me.