Python Find And Replace Strings In Files With Argument That The String Is Quoted And Not Part Of Bigger String

i need a solution to the following problem. I want to replace a dynamic string if found in a file but only if there are quotes surrounding the string, either next to it or with max

Solution 1:

A regular expression would be a good tool for such a task. Always take care to express them clearly. Regular expressions can quickly become puzzling and hard to debug.

import re

original = 'testing'
replacement = 'posting'

line1 = 'This is one line with some words for testing purposes'
line2 = 'this is the seconds "testing" function.'
line3 = 'that is one more " testing" line'
line4 = '"testing"'
line5 = '"  testing"'
line6 = '"testing  "'
line7 = '"  testing  "'

lines = [line1, line2, line3, line4, line5, line6, line7]

starts_with_parentheses = '^"'
ends_with_parentheses = '"$'
one_space = ' {1}'
two_spaces = ' {2}'
none_one_or_two_spaces = '(|{}|{})'.format(one_space, two_spaces)

query = starts_with_parentheses \
        + none_one_or_two_spaces \
        + original \
        + none_one_or_two_spaces \
        + ends_with_parentheses

for line in lines:
    match = re.search(query, line)
    if match:
        line = line.replace(original, replacement)

    print(line)

Outputs:

This is one line with some words for testing purposes
thisis the seconds "testing" function.
that is one more " testing" line
"posting""  posting""posting  ""  posting  "