Counter to the PythonSpeed/PerformanceTips, on python 2.4 the following string concatenation is almost twice as fast:

   1 from time import time
   2 t = time()
   3 
   4 s = 'lksdajflakjdsflku09uweoir'
   5 for x in range(40):
   6     s += s[len(s)/2:]
   7     
   8 print 'duration:', time()-t

as:

   1 from time import time
   2 t = time()
   3 
   4 s = 'lksdajflakjdsflku09uweoir'
   5 for x in range(40):
   6     s = "".join((s, s[len(s)/2:]))
   7     
   8 print 'duration:', time()-t

On the win32 Python 2.4 I'm seeing the join sample above complete in less than half the time of the concatenating sample.

• -db

Usually the join() is located outside the loop, that code makes this extremely hard though (becuase of the self-referencing of the generated string). But that situation is not the norm. -- JürgenHermann DateTime(2005-08-01T06:07:51Z)