I wrote a handy-dandy function (see below) called "strip_pairs" for stripping
matching pairs of characters from the beginning and end of a string. This
function works, but I would like to be able to invoke it as a string method
rather than as a function. Is this possible?
def strip_pairs(s=None, open='([{\'"', close=')]}\'"'):
"""This function strips matching pairs of characters from the beginning
and
end of the input string `s`. `open` and `close` specify corresponding
pairs
of characters, and must be equal-length strings. If `s` begins with a
character in `open` and ends with the corresponding character in `close`,
both are removed from the string. This process continues until no
further
matching pairs can be removed."""
if len(open) != len(close): raise Exception, \
'\'open\' and \'close\' arguments must be strings of equal length.'
# If input is missing or is not of type `str` (or `unicode`), return
None:
if s is None or not isinstance(s,(str,unicode)): return None
while len(s) >= 2:
# Check whether first character of `s` is in `open`:
i= open.find(s[0])
# If `s` does not begin with a character from `open`, there are no
more
# pairs to be stripped:
if i == -1: break
# If `s` does not begin and end with matching characters, there are no
# more pairs to be stripped:
if s[-1] != close[i]: break
# Strip the first and last character from `s`:
s= s[1:-1]
return s
--
View this message in context:
http://old.nabble.com/how-to-convert-string-function-to-string-method--tp26673209p26673209.html
Sent from the Python - python-list mailing list archive at Nabble.com.
--
http://mail.python.org/mailman/listinfo/python-list
