sorry, my mistake it runs faster (looking at the wrong line of code). But the first two solutions are still faster.
On Sat, May 8, 2010 at 12:48 PM, Daniel Skinner <dasac...@gmail.com> wrote: > That solution actually runs slower then the generator method. > > > On Sat, May 8, 2010 at 12:33 PM, Shashank Singh < > shashank.sunny.si...@gmail.com> wrote: > >> >> >> On Sat, May 8, 2010 at 10:49 PM, dasacc22 <dasac...@gmail.com> wrote: >> >>> Hi >>> >>> This is a simple question. I'm looking for the fastest way to >>> calculate the leading whitespace (as a string, ie ' '). >>> >>> Here are some different methods I have tried so far >>> --- solution 1 >>> >>> a = ' some content\n' >>> b = a.strip() >>> c = ' '*(len(a)-len(b)) >>> >> >> use lstrip if you want to remove leading whitespaces only. >> strip removes trailing white spaces too >> >>> >>> --- solution 2 >>> >>> a = ' some content\n' >>> b = a.strip() >>> c = a.partition(b[0])[0] >>> >>> --- solution 3 >>> >>> def get_leading_whitespace(s): >>> def _get(): >>> for x in s: >>> if x != ' ': >>> break >>> yield x >>> return ''.join(_get()) >>> >> >> why do you need a generator (and as you mentioned the extra function call >> overheads)? >> >> How about this? >> >> def get_leading_whitespaces(s): >> count = 0 >> for c in s: >> if c != ' ': break >> count += 1 >> return ' ' * count >> >> >>> >>> --- >>> >>> Solution 1 seems to be about as fast as solution 2 except in certain >>> circumstances where the value of b has already been determined for >>> other purposes. Solution 3 is slower due to the function overhead. >>> >>> Curious to see what other types of solutions people might have. >>> >>> Thanks, >>> Daniel >>> -- >>> http://mail.python.org/mailman/listinfo/python-list >>> >> >> >> >> -- >> Regards >> Shashank Singh >> Senior Undergraduate, Department of Computer Science and Engineering >> Indian Institute of Technology Bombay >> shashank.sunny.si...@gmail.com >> http://www.cse.iitb.ac.in/~shashanksingh >> > >
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