[Python-Dev] Proof of the pudding: str.partition()

Michael Chermside mcherm at mcherm.com
Wed Aug 31 13:55:35 CEST 2005

Raymond's original definition for partition() did NOT support any
of the following:

   (*) Regular Expressions
   (*) Ways to generate just 1 or 2 of the 3 values if some are
       not going to be used
   (*) Clever use of indices to avoid copying strings
   (*) Behind-the-scenes tricks to allow repeated re-partitioning
       to be faster than O(n^2)

The absence of these "features" is a GOOD thing. It makes the
behavior of partition() so simple and straightforward that it is
easily documented and can be instantly understood by a competent
programmer. I *like* keeping it simple. In fact, if anything, I'd
give UP the one fancy feature he chose to include:

   (*) An rpartition() function that searches from the right

...except that I understand why he included it and am convinced
by the arguments (use cases can be demonstrated and people would
expect it to be there and complain if it weren't).

Simplicity and elegence are two of the reasons that this is such
an excellent proposal, let's not lose them. We have existing
tools (like split() and the re module) to handle the tricky

-- Michael Chermside

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