On Jul 20, 5:00 am, Andrew Freeman <[EMAIL PROTECTED]> wrote: > Andrew Freeman wrote: > > John Machin wrote: > >> A couple of points: > >> (1) Instead of search(r'^blahblah', ...) use match(r'blahblah', ...) > >> (2) You need to choose your end-anchor correctly; your pattern is > >> permitting a newline at the end: > > I forgot to change search to match. This should be better: > > def match(var): > if re.match(r'[LRM]*\Z', var): > return True > else: > return False
A bit wordy ... if blahblah: return True else: return False can in total generality be replaced by: return blahblah > > I was also thinking if you had a list of these items needing to be > verified you could use this: You could, but I suggest you don't use it in a job interview :-) > >>> l = ['LLMMRR', '00thLL', 'L', '\n'] (1) Don't use 'L'.lower() as a name; it slows down reading as people need to fire up their mental parser to distinguish it from the result of 3 - 2 > >>> out = [] > >>> map(lambda i: match(i)==False or out.append(i), l) (2) Read PEP 8 (3) blahblah == False ==> not blahblah (4) You didn't show the output from map() i.e. something like [None, True, None, True] (5) or out.append(...) is a baroque use of a side-effect, and is quite unnecessary. If you feel inexorably drawn to following the map way, read up on the filter and reduce functions. Otherwise learn about list comprehensions and generators. > >>> print out > ['LLMMRR', 'L'] > Consider this: >>> import re >>> alist = ['LLMMRR', '00thLL', 'L', '\n'] >>> zeroplusLRM = re.compile(r'[LRM]*\Z').match >>> filter(zeroplusLRM, alist) ['LLMMRR', 'L'] >>> [x for x in alist if zeroplusLRM(x)] ['LLMMRR', 'L'] >>> Cheers, John -- http://mail.python.org/mailman/listinfo/python-list
