Question

I have a string in which I need to add a ‘\’ in front of every ‘[‘ or ‘]’, except if the brackets enclose an x like this: ‘[x]’. In the other cases, the brackets will always enclose a number.

Example:
'Foo[123].bar[x]' should become 'Foo\[123\].bar[x]'.

What is the best way to achieve this? Thanks a lot on beforehand.

Answer 1

Something like this ought to work:

>>> import re
>>>
>>> re.sub(r'\[(\d+)\]', r'\[\1\]', 'Foo[123].bar[x]')
'Foo\\[123\\].bar[x]'