how to delete all lines after a certain string in a file and then add some more lines using python

Question

I want to delete all the lines in a file smart.txt and then add some strings of my own. smart.txt contains alot of lines.

I tried

import sys
import os

output=[]
f= open(smart.txt, 'r')
for line in f:
 output.append(line)
 if '*** P R O P E R T I E S ***' in line: break
f=open(smart.txt, 'w')
[f.write(data) for data in output]
f.write('*** Inclusions ***\n ')
f.write('*** Permanent  ***\n ')
f.close()

I am getting an error

f= open(smart.txt, 'r')
NameError: name 'smart' is not defined

cannot figure out because smart.txt is present in the same directory.

Any suggestions?

@all Look, i found this... http://stackoverflow.com/questions/4706499/how-do-you-append-to-a-file-in-python?rq=1 I hope you get my point! and look the subscribers to this question! ;) — Hamad Hassan, Apr 08 '16 at 20:30
what do you think considering you already accepted and asnwer? — Padraic Cunningham, Apr 08 '16 at 20:51
@PadraicCunningham, I already considered -2 for that. How about editing your answer for perfect grammer and typos? You did not even bother to complete the answer... there is no question as stupid mind it, you also learnt it! — Hamad Hassan, Apr 11 '16 at 07:49

Farhan.K · Accepted Answer · 2016-04-07T10:55:23.150

1

You need to use 'smart.txt' instead of smart.txt when you're opening the file. So you would change f= open(smart.txt, 'r') to f= open('smart.txt', 'r').

Also you should use with open('smart.txt', 'r') as f to automatically close the file when you are done with it.

Tutorial on file io: link

edited Apr 07 '16 at 10:55

answered Apr 07 '16 at 10:49

Farhan.K

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how to delete all lines after a certain string in a file and then add some more lines using python

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