Htykuut

I'm trying to modify a specific line in a js file using python.

Here's the js file :

...

hide: [""]

...

Here's my python code :

with open('./config.js','r') as f:

   lines = f.readlines()



with open('./config.js','w') as f:

   for line in lines:

       line = line.replace('hide', 'something')

       f.write(line)

So it works but this is not what I want to do.

I want to write 'something' between the brackets and not replace 'hide'.

So I don't know how to do it: Do I have to replace the whole line or can I just add a word between the brackets?

Thanks

If you want to replace text at this exact line you could just do:

with open('./config.js','r') as f:

   lines = f.readlines()



with open('./config.js','w') as f:

   new_value = 'Something New'

   for line in lines:

       if line.startswith('hide'):

           line = 'hide: ["{}"]'.format(new_value)

       f.write(line)

or alternatively in the conditional

           if line.startswith('hide'):

               line = line.replace('""', '"Something new"')

Here's way to replace any value in brackets for hide that starts with any spacing.

lines = '''

first line

            hide: [""]

       hide: ["something"]

last line

'''

new_value = 'new value'



for line in lines.splitlines():

    if line.strip().startswith('hide'):

       line = line[:line.index('[')+2] + new_value + line[line.index(']')-1:]

    print(line)

Output:

first line

            hide: ["new value"]

       hide: ["new value"]

last line

If hide: [""] is not ambiguous, you could simply load the whole file, replace and write it back:

newline = 'Something new'



with open('./config.js','r') as f:

   txt = f.read()



txt = txt.replace('hide: [""]', 'hide: ["' + newline + '"]')



with open('./config.js','w') as f:

   f.write(txt)

As long as you don't have "hide" anywhere else in the file, then you could just do

with open('/config.js','r') as f:

    lines = f.readlines()



with open('./config.js','w') as f:

    for line in lines:

        line = line.replace('hide [""]', 'hide ["something"]')

        f.write(line)

You can do this using re.sub()

import re

with open('./config.js','r') as f:

   lines = f.readlines()



with open('./config.js','w') as f:

   for line in lines:

       line = re.sub(r'([")("])', r'1' + 'something' + r'2', line)

       f.write(line)

It works by searching for a regular expression, but forms a group out of what you want on the left (([")) and the right (("])). You then concatenate these either side of the text you want to insert (in this example 'something').

The bounding ( ) makes a group which can be accessed in the replace with r'1', then second group is r'2'.

You can use fileinput and replace it inplace:

import fileinput

import sys



def replaceAll(file,searchExp,replaceExp):

    for line in fileinput.input(file, inplace=1):

        if searchExp in line:

            line = line.replace(searchExp,replaceExp)

        sys.stdout.write(line)



replaceAll("config.js",'hide: [""]','hide: ["something"]')

Reference