Need help using callables and setup in timeit.Timer

Matthew Wilson matt at tplus1.com
Wed May 12 10:23:29 EDT 2010


I want to time some code that depends on some setup.  The setup code
looks a little like this:

    >>> b = range(1, 1001)

And the code I want to time looks vaguely like this:

    >>> sorted(b)

Except my code uses a different function than sorted.  But that ain't
important right now.

Anyhow, I know how to time this code as long as I pass in strings to timeit:

    >>> import timeit
    >>> t = timeit.Timer("sorted(b)", "b = range(1, 1001)")
    >>> min(t.repeat(3, 100))

How do I use a setup callable and have it put stuff into the namespace
that the stmt callable can access?

In other words, I want to do the same thing as above, but using
callables as the parameters to timeit.Timer, not strings of python code.

Here's my long-run goal.  I want to reuse code from my unit tests to
test performance:

    import unittest
    class TestSorting(unittest.TestCase):

        def setUp(self):
            self.b = range(1, 1001)

        def test_sorted(self):
            sorted(self.b)

I expect to have to do a little work.  The timeit setup will need to
make an instance of TestSorting and somehow the stmt code will have to
use that particular instance.

Once I understand how to have the timeit setup put stuff into the same
namespace as the timeit stmt, I'll attack how to translate
unittest.TestCase instances into something that can feed right into
timeit.Timer.

Matt






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