Code that ought to run fast, but can't due to Python limitations.

[Paul Rubin]

Stefan Behnel <stefan_ml at behnel.de> writes:
> > The series of tests is written that way because there is no case
> > statement available.  It is essentially switching on a bunch of
> > character constants and then doing some additional tests in each
> > branch.
> Although doing some of the tests first and then checking the input
> conditionally might be faster here.

That is essentially what happens.  There are a bunch of tests of the
form
   if data=='<' and [some other stuff]: ...

Because of short-circuit evaluation of "and", the additional tests
only happen once the character has been matched.