the mystery of dirname()

[Shashwat Anand]

But this is posixpath, right ? So '//x' like path will not occur as far as I
guess ?

On Sat, Feb 20, 2010 at 8:35 AM, MRAB <python at mrabarnett.plus.com> wrote:

> 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 ''.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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