How to edit a line in a notepad file using python

Question

I am trying to edit a specific line of a notepad file using Python 3. I can read from any part of the file and write to the end of it, however whenever I have tried editing a specific line, I am given the error message 'TypeError: 'int' object is not subscriptable'. Does anybody know how I could fix this?

#(This was my first attempt)
f = open('NotepadTester.txt', 'w')
Edit = input('Enter corrected data')
Line = int(input('Which line do you want to edit?'))
f.write(Edit)[Line-1]
f.close()
main()

#(This was my second attempt)    
f = open('NotepadTester.txt', 'w')
Line = int(input('Which line do you want to edit?'))
Edit = input('Enter corrected data')
f[Line-1] = (Edit)
main()

Answer 1

you can't directly 'edit' a line in a text file as far as I know. what you could do is read the source file src to a variable data line-by-line, edit the respective line and write the edited variable to another file (or overwrite the input file) dst.

EX:

# load information
with open(src, 'r') as fobj:
    data = fobj.readlines() # list with one element for each text file line

# replace line with some new info at index ix
data[ix] = 'some new info
'

# write updated information      
with open(dst, 'w') as fobj:
    fobj.writelines(data)

...or nice and short (thanks to Aivar Paalberg for the suggestion), overwriting the input file (using open with r+):

with open(src, 'r+') as fobj:
    data = fobj.readlines()
    data[ix] = 'some new info
'
    fobj.seek(0) # reset file pointer...
    fobj.writelines(data)