Edit text in file in python

Question

I am new to python and working on to get input and edit a file with python. The value I want to edit is "web-iphone" with the text I get from input.

Code so far:

web = raw_input("Enter value")

The file: test.py

    local {
            value web-iphone
    }

https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files — user3467349, Feb 21 '15 at 11:59
Do I have to overwrite the file or is it possible to edit text in the file ? — user3270211, Feb 21 '15 at 12:00
Depends what you mean by edit - a file can be appended to, or parts can be replaced, it cannot be inserted to. Generally you want to over-write the file. — user3467349, Feb 21 '15 at 12:02
How can I replace the part "web-iphone" any resources I can look at ? — user3270211, Feb 21 '15 at 12:06
http://stackoverflow.com/questions/27123091/delete-a-line-from-a-file-in-place/27123361#27123361 lists basic ways in which you can edit a file — ivan_pozdeev, Feb 21 '15 at 12:08

Leafthecat · Accepted Answer · 2015-02-21T14:36:34.500

2

Edit: What you are asking is clearer now, refined my answer.

To get a file's contents:

def read_file(filename):
  return open(filename).read()

And to write to a file:

def write_file(filename, toWrite):
  file = open(filename, 'w')
  file.write(toWrite)
  file.close()

So to replace "web-iphone" with whatever the user typed in you could do:

Web = raw_input("Enter a value ")
Replaced = read_file("myfile.txt").replace("web-iphone", Web)
write_file("myfile.txt", Replaced)

For your comment:

newInput = raw_input("Enter a value ")
OldFile = read_file("myfile.txt")
value = OldFile.find("value"+6)
newFile = OldFile[:value] + newInput + OldFile[OldFile.find("\n",value+1):]

edited Feb 21 '15 at 14:36

answered Feb 21 '15 at 12:07

Leafthecat

326
1
8

If I dont know the value to be replaced but I know the column? As in shell - awk '{ print $2 }' is that possible ? To replace a specific column in a line ? – user3270211 Feb 21 '15 at 14:02
It is possible, I will add it to the bottom of my answer for the sake of formatting, hold on a moment please. – Leafthecat Feb 21 '15 at 14:06
Since I always want "value" in that file stay, but want to change the text after value to for example web-iphone. – user3270211 Feb 21 '15 at 14:17
Oh, ok . I'll have that added to my answer in a minute. – Leafthecat Feb 21 '15 at 14:26
Thanks for your precious time. – user3270211 Feb 21 '15 at 14:36
No problem :) The code I just posted should replace anything after value, and before the next line, with the user input. – Leafthecat Feb 21 '15 at 14:38
On the value+6 i get this error: TypeError: cannot concatenate 'str' and 'int' objects – user3270211 Feb 21 '15 at 14:50
1

Oops, move the +6 outside the parentheses. – Leafthecat Feb 21 '15 at 15:28

Edit text in file in python

1 Answers1