On 10/7/2014 9:41 PM, Steven D'Aprano wrote:
Every Python operator has a function version in the operator module:
operator + has function operator.add;
operator - has function operator.sub;
operator * has function operator.mul;
and so forth. Only, that's not quite right... according to the
documentation, the "official" functions are actually:
operator.__add__;
operator.__sub__;
operator.__mul__;
etc., with the underscore-less versions being provided as a convenience.
Was anyone aware of this?
Of course. It has bugged me a bit for years. Messy.
Is there anyone who uses or prefers the dunder versions?
I don't and don't, and that seems to be true of other core devs: there
are no non-test uses of the dunder methods in the stdlib. Grepping
/lib/*.py recursively for 'operator.' gives 540 hits, most for
operator.someop. Grepping the same for 'operator.__' returns 4 hits for
operator.__name__ and .__doc__ (not operators) and these 6 tests:
C:\Programs\Python34\Lib\test\test_richcmp.py: 88: "lt": (lambda
a,b: a< b, operator.lt, operator.__lt__),
C:\Programs\Python34\Lib\test\test_richcmp.py: 89: "le": (lambda
a,b: a<=b, operator.le, operator.__le__),
C:\Programs\Python34\Lib\test\test_richcmp.py: 90: "eq": (lambda
a,b: a==b, operator.eq, operator.__eq__),
C:\Programs\Python34\Lib\test\test_richcmp.py: 91: "ne": (lambda
a,b: a!=b, operator.ne, operator.__ne__),
C:\Programs\Python34\Lib\test\test_richcmp.py: 92: "gt": (lambda
a,b: a> b, operator.gt, operator.__gt__),
C:\Programs\Python34\Lib\test\test_richcmp.py: 93: "ge": (lambda
a,b: a>=b, operator.ge, operator.__ge_
If there a back-compatibility excuse? I cannot remember what operator
had in 1.4 or whenever it was added, if after that.
--
Terry Jan Reedy
--
https://mail.python.org/mailman/listinfo/python-list
