coord_match.py

import re

number = r'\d+ (?: \. \d*)?'  # one or more digits, followed by an optional dot and zero or more digits
coord2 = re.compile(r'\s* \( \s* (?P<lat> {number}) \s* , \s* (?P<lon> {number}) \s* \) \s*'.format(number=number), re.VERBOSE)

s = '(23.34, 11)'
match = coord2.match(s)
if match:
    lat, lon = float(match.group('lat')), float(match.group('lon'))
    print('Captured coordinates {:0.2f} {:0.2f}'.format(lat, lon))
    
# A more verbose version with comments
coord = re.compile(r"""
    \s*                       # optional whitespace
    \(                        # opening bracket
    \s*                       # optional whitespace
    (?P<lat>                  # capture latitude
        \d+                     # digits
        (?:                     # optional decimal part starts, don't capture it
          \.                      # a dot
          \d*                     # optional decimal digits
        )?                      # optional decimal part ends
    )                         # end of latitude capture
    \s*                       # optional whitespace
    ,                         # coma separating coordinates
    \s*                       # optional whitespace
    (?P<lon>                  # capture longitude
        \d+                     # digits
        (?:                     # # optional decimal part starts, don't capture it
          \.                      # a dot
          \d*                     # optional decimal digits
        )?                      # optional decimal part ends
    )                         # end of longitude capture    
    \s*                       # optional whitespace
    \)                        # closing bracket
    \s*                       # optional whitespace
""", re.VERBOSE)

match = coord.match(s)
if match:
    lat, lon = float(match.group('lat')), float(match.group('lon'))
    print('Captured coordinates {:0.2f} {:0.2f}'.format(lat, lon))