First, avoid using str as a variable name. str already has a meaning in Python and by defining it to be something else you will confuse people.

Having said that you can use the following regular expression:

>>> import re
>>> print re.findall(r'\[([^]]*)\]', s)
['Service Current', 'Service', '9991', '1.22']

This works as follows:

\[   match a literal [
(    start a capturing group
[^]] match anything except a closing ]
*    zero or more of the previous
)    close the capturing group
\]   match a literal ]

An alternative regular expression is:

r'\[(.*?)\]'

This works by using a non-greedy match instead of matching anything except ].

you can use regex

import re
s = re.findall('\[(.*?)\]', str)

re.findall(r'\[([^\]]*)\]', str)