Question

Let’s say, that I have:

string= '{'id': '1'}'

and now using strings like in Perl/sed I would like to get

string=id

(in Perl it would look like string=~s/\{\'([a-zA-Z0-9]*)\'.*$)/\1/)

Could you please give me a little insight how to do that in python? I expect that the regex syntax will be similar, but I’m not sure about the python syntax and what imports should I use, I’m quite beginner in Python 🙂 Thank you a lot 🙂

Answer 1

In Python you’d use the re module for regular expression operations. I modified your regular expression a bit, but generally, this is how regular expression replacement can be done in python:

>>> import re
>>> s = "{'id': '1'}"
>>> re.sub(r"{'([^\']*)'.*$", r'\1', string)
'id'

The sub() function accepts the regex first, then the replacement and finally the string. The documentation of the re module has some more information:
http://docs.python.org/library/re.html

The r prefix to the strings passed as arguments basically tells Python to treat them as “raw” strings, where most backslash escape sequences are not interpreted.