On May 8, 1:16 pm, dasacc22 <dasac...@gmail.com> wrote:
> On May 8, 12:59 pm, Patrick Maupin <pmau...@gmail.com> wrote:
>
>
>
> > On May 8, 12:19 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))
>
> > > --- 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())
>
> > > ---
>
> > > 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
>
> > Well, you could try a solution using re, but that's probably only
> > likely to be faster if you can use it on multiple concatenated lines.
> > I usually use something like your solution #1. One thing to be aware
> > of, though, is that strip() with no parameters will strip *any*
> > whitespace, not just spaces, so the implicit assumption in your code
> > that what you have stripped is spaces may not be justified (depending
> > on the source data). OTOH, depending on how you use that whitespace
> > information, it may not really matter. But if it does matter, you can
> > use strip(' ')
>
> > If speed is really an issue for you, you could also investigate
> > mxtexttools, but, like re, it might perform better if the source
> > consists of several batched lines.
>
> > Regards,
> > Pat
>
> Hi,
>
> thanks for the info. Using .strip() to remove all whitespace in
> solution 1 is a must. If you only stripped ' ' spaces then line
> endings would get counted in the len() call and when multiplied
> against ' ', would produce an inaccurate result. Regex is
> significantly slower for my purposes but ive never heard of
> mxtexttools. Even if it proves slow its spurred my curiousity as to
> what functionality it provides (on an unrelated note)
Could you reorganize your code to do multiple lines at a time? That
might make regex competitive.
Regards,
Pat
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