For Windows XP SP3:

v = 'add 1 to 4.56'
import re
r=re.search("([0-9]+)\D+(\d+\.\d+)","add 1 to 4.56")
r
<_sre.SRE_Match object at 0x00BED920>
r.groups()
('1', '4.56')
dir(r)
[]

in pyhton 2.5 it shows:
['__copy__', '__deepcopy__', 'end', 'expand', 'group', 'groupdict', 'gro
ups', 'span', 'start']

The cause is that this object use a custom tp_getattr slot, and use
Py_FindMethod from there. and py3k removed the special "__methods__"
lookup that allowed to lists these items.

Of course, nowadays the way to add methods is not to put them in
tp_getattr, but in a tp_methods slot.

Done in several changes: r64672 r64674 r64681.

Now the dir() is even more complete than before. I get:
['__class__', '__copy__', '__deepcopy__', '__delattr__', '__doc__',
'__eq__', '__format__', '__ge__', '__getattribute__', '__gt__',
'__hash__', '__init__', '__le__', '__lt__', '__ne__', '__new__',
'__reduce__', '__reduce_ex__', '__repr__','__setattr__', '__sizeof__',
'__str__', '__subclasshook__', 'end', 'endpos', 'expand', 'group',
'groupdict', 'groups', 'lastgroup', 'lastindex', 'pos', 're', 'regs',
'span', 'start', 'string']