[Python-Dev] [Python-checkins] cpython (3.3): Issue #16045: add more unit tests for built-in int() (original) (raw)

Chris Jerdonek chris.jerdonek at gmail.com
Sun Dec 23 22:47:46 CET 2012

On Sun, Dec 23, 2012 at 12:03 PM, Terry Reedy <tjreedy at udel.edu> wrote:

+ # For example, PyPy 1.9.0 raised TypeError for these cases because it + # expects x to be a string if base is given. + @support.cpythononly + def testbaseargwithnoxarg(self): + self.assertEquals(int(base=6), 0) + # Even invalid bases don't raise an exception. + self.assertEquals(int(base=1), 0) + self.assertEquals(int(base=1000), 0) + self.assertEquals(int(base='foo'), 0) I think the above behavior is buggy and should be changed rather than frozen into CPython with a test. According to the docs, PyPy does it right.

I support further discussion here. (I did draft the patch, but it was a first version. I did not commit the patch.)

The current online doc gives the signature as int(x=0) int(x, base=10) <>

The 3.3.0 docstring says "When converting a string, use the optional base. It is an error to supply a base when converting a non-string."

One way to partially explain CPython's behavior is that when base is provided, the function behaves as if x defaults to '0' rather than 0. This is similar to the behavior of str(), which defaults to b'' when encoding or errors is provided, but otherwise defaults to '':

http://docs.python.org/dev/library/stdtypes.html#str

Certainly, accepting any object as a base, violating "The allowed values are 0 and 2-36." just because giving a base is itself invalid is crazy.

For further background (and you can see this is the 2.7 commit), int(base='foo') did raise TypeError in 2.7, but this particular case was relaxed in Python 3.

--Chris

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