Christoph Zwerschke <[EMAIL PROTECTED]> wrote:
> In Python programs, you will quite frequently find code like the
> following for removing a certain prefix from a string:
>
> if url.startswith('http://'):
> url = url[7:]
If I came across this code I'd want to know why they weren't using
urlparse.urlsplit()...
>
> Similarly for stripping suffixes:
>
> if filename.endswith('.html'):
> filename = filename[:-5]
... and I'd want to know why os.path.splitext() wasn't appropriate here.
>
> My problem with this is that it's cumbersome and error prone to count
> the number of chars of the prefix or suffix. If you want to change it
> from 'http://' to 'https://', you must not forget to change the 7 to 8.
> If you write len('http://') instead of the 7, you see this is actually
> a DRY problem.
>
> Things get even worse if you have several prefixes to consider:
>
> if url.startswith('http://'):
> url = url[7:]
> elif url.startswith('https://'):
> url = url[8:]
>
> You can't take use of url.startswith(('http://', 'https://')) here.
>
No you can't, so you definitely want to be parsing the URL properly. I
can't actually think of a use for stripping off the scheme without either
saving it somewhere or doing further parsing of the url.
--
http://mail.python.org/mailman/listinfo/python-list
