pattern = "(([ef]|([gh]d*(ad*[gh]d)*b))d*b([ef]d*b|d*)*c)"

matches = re.finditer(pattern, string)
for match in matches:
    print "(%d-%d): %s" % (match.start(), match.end(), match.group())

Traceback (most recent call last):
  File "code.py", line 133, in <module>
    main(sys.argv[1:])
  File "code.py", line 106, in main
    for match in matches:
KeyboardInterrupt

ddddddeddbedddbddddddddddddddddddddddddddddddddddd

ddddddeddbedddbdddddddddddddddddddddddd

ddddddeddbedddbdddddddddddddd

([ef]|([gh]d*(ad*[gh]d)*b))d*b

|

(([ef]|([gh]d*(ad*[gh]d)*b))d*b([ef]d*b|d*)*c)

(([ef]|([gh]d*(ad*[gh]d)*b))d*b([ef]d*bd*)*c)

import re

string = "ddddddeddbedddbddddddddddddddddddddddddddddddddddd"
pattern = "(([ef]|([gh](a[gh])*b))b([ef]b)*c)"
matches = re.finditer(pattern, re.sub("d+", "", string))
for match in matches:
    print "(%d-%d): %s" % (match.start(), match.end(), match.group())