backslashes in escape rules

[Graham Percival]

Quick check for convert rules, changing "\foo" to "\bar".

   The early rules use escape chars:
@rule ((1, 0, 1), '\\accidentals -> \\keysignature,
specialaccidentals -> keyoctaviation')
def conv (str):
    str = re.sub ('\\\\accidentals', '\\\\keysignature',str)

  But the later rules don't use any backslashes:
@rule ((2, 11, 48), "\\compressMusic -> \\scaleDurations")
def conv (str):
    str = re.sub (r"compressMusic", r"scaleDurations", str)
    return str


Which should I use?  "foo", "\\foo", or "\\\\foo" ?

Cheers,
- Graham