import re

# Regular expression for recognizing HEXEWKB and WKT.  A prophylactic measure

# to prevent potentially malicious input from reaching the underlying C

# library.  Not a substitute for good web security programming practices.

hex_regex = re.compile(r'^[0-9A-F]+$', re.I)

wkt_regex = re.compile(r'^(SRID=(?P<srid>\d+);)?'

                       r'(?P<wkt>'

                       r'(?P<type>POINT|LINESTRING|LINEARRING|POLYGON|MULTIPOINT|MULTILINESTRING|MULTIPOLYGON|GEOMETRYCOLLECTION)'

                       r'[ACEGIMLONPSRUTYZ\d,\.\-\(\) ]+)$',

                       re.I)

json_regex = re.compile(r'^(\s+)?\{[\s\w,\[\]\{\}\-\."\':]+\}(\s+)?$')