On 21/08/11 19:14:19, Irmen de Jong wrote:
What the precise difference (semantics and speed) is between the BINARY_ADD and INPLACE_ADD opcodes, I dunno. Look in the Python source code or maybe someone knows it from memory :-)
There is a clear difference in semantics: BINARY_ADD always produces a new object, INPLACE_ADD may modify its left-hand operand in situ (if it's mutable). Integers are immutable, so for integers the semantics are the same, but for lists, for example, the two are different: >>> x = [2, 3, 5, 7] >>> y = [11, 13] >>> x+y [2, 3, 5, 7, 11, 13] >>> x [2, 3, 5, 7] # x still has its original value >>> x += y >>> x [2, 3, 5, 7, 11, 13] # x is now modified >>> For integers, I would not expect a measurable difference in speed. Hope this helps, -- HansM -- http://mail.python.org/mailman/listinfo/python-list
