>>> s='''Lisf can be dreams,
 ...Lisfe can be great thoughts;
 ...Life can mean a person
 ...Sitting in a count.''' r=re.compile("\\b(?P<first>\w+)a(\w+)\\b")

>>> m=r.search(s)
 >>> m

 <_sre.SRE_Match object; span=(5, 8), match='can'>

 >>> m.start()

 5

 >>> m=r.search(s,9)

 >>> m.start()

 12

 >>> m.start(1)

 12

 >>> m.start(2)

 16

 >>> m.end(1)

 15

 >>> m.end()

 18

 >>> m.span()

 (12, 18)

 >>> s[12:18]

 'dreams'

 >>> m.span(2)

 (16, 18)