MRAB
2/20/2010 3:06:00 AM
Shashwat Anand wrote:
> In the following code sample :
>
> def dirname(p):
>
> """Returns the directory component of a pathname"""
> i = p.rfind('/') + 1
>
> head = p[:i]
> if head and head != '/'*len(head):
>
> head = head.rstrip('/')
>
> return head
>
> def dirname1(p):
> i = p.rfind('/') + 1
>
> head = p[:i]
> if head != '/':
>
> return head.rstrip('/')
> return head
>
> if __name__ == "__main__":
> p1 = '/Users/l0nwlf/Desktop'
>
> p2 = './'
> p3 = '/'
> p4 = '.'
>
> print dirname(p1), dirname1(p1)
>
> print dirname(p2), dirname1(p2)
>
> print dirname(p3), dirname1(p3)
>
> print dirname(p4), dirname1(p4)
>
> OUTPUT:
>
> /Users/l0nwlf /Users/l0nwlf
> . .
> / /
>
> dirname() is a function taken from /Lib/posixpath.py. However i did not quite understood the usage of "if head and head != '/'*len(head):" and replaced it with more obvious way in dirname1().
>
> Am I right to do so ? Is dirname1() more pythonic ? Did I missed any edge cases here ?
>
What if the path is '//x'? The current dirname would return '//',
whereas dirname1 would return ''.