[ python-Bugs-1560179 ] Better/faster implementation of os.path.basename/dirname

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Bugs item #1560179, was opened at 2006-09-17 07:55
Message generated for change (Comment added) made by josiahcarlson
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Category: None
Group: None
Status: Closed
Resolution: Accepted
Priority: 5
Submitted By: Michael Gebetsroither (einsteinmg)
Assigned to: Nobody/Anonymous (nobody)
Summary: Better/faster implementation of os.path.basename/dirname

Initial Comment:
hi,

basename/dirname could do better (especially on long 
pathnames)

def basename(p):
    return split(p)[1]

def dirname(p):
    return split(p)[0]

both construct base and dirname and discard the unused 
one.

what about that?

def basename(p):
    i = p.rfind('/') + 1
    return p[i:]

def dirname(p):
    i = p.rfind('/') + 1
    return p[:i]

greets,
michael

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Comment By: Josiah Carlson (josiahcarlson)
Date: 2006-10-16 15:23

Message:
Logged In: YES 
user_id=341410

I note that in the current SVN, dirname uses a test of "if
head and head != '/'*len(head):" to check for the path being
all /, could be replaced by "if head and head.count('/') !=
len(head):", but it probably isn't terribly important.

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Comment By: Georg Brandl (gbrandl)
Date: 2006-10-12 06:08

Message:
Logged In: YES 
user_id=849994

Committed in rev. 52316.

----------------------------------------------------------------------

Comment By: Michael Gebetsroither (einsteinmg)
Date: 2006-09-18 05:42

Message:
Logged In: YES 
user_id=1600082

posixpath with this patch passes all test from 
test_posixpath cleanly.

benchmark:
basename( 310 ) means basename called with a 310 chars long 
path

sum = 0.0435626506805 min = 4.19616699219e-05 
posixpath.basename( 310 )
sum = 0.152147769928 min = 0.00014591217041 
posixpath_orig.basename( 310 )

sum = 0.0436658859253 min = 4.07695770264e-05 
posixpath.basename( 106 )
sum = 0.117312431335 min = 0.000112771987915 
posixpath_orig.basename( 106 )

sum = 0.0426909923553 min = 4.07695770264e-05 
posixpath.basename( 21 )
sum = 0.113305330276 min = 0.000110864639282 
posixpath_orig.basename( 21 )

sum = 0.12392115593 min = 0.000121831893921 
posixpath.dirname( 310 )
sum = 0.152860403061 min = 0.00014591217041 
posixpath_orig.dirname( 310 )

sum = 0.0942873954773 min = 9.08374786377e-05 
posixpath.dirname( 106 )
sum = 0.114937067032 min = 0.000111818313599 
posixpath_orig.dirname( 106 )

sum = 0.0918889045715 min = 8.79764556885e-05 
posixpath.dirname( 21 )
sum = 0.114675760269 min = 0.000109910964966 
posixpath_orig.dirname( 21 )

greets

----------------------------------------------------------------------

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