20.10.20 18:05, Marco Sulla пише: > I read these three C api functions, They are similar, because they all > construct a tuple[1]. > > IMHO, Py_BuildValue is more simple to use than PyTuple_Pack that is more > simple to use than PyTuple_New. > > Where to use one or the other? What's the relative performance of the three > functions?
Py_BuildValue is the most powerful (it can creates not only tuple, it can create items from V integers, strings, etc, it can decrement refcount), but it is slower. It is used when the performance less important than saving few lines of code. PyTuple_Pack() is convenient when you create a tuple from constant number of Python objects. It is a good compromise with readability and performance. PyTuple_New is used for creating a variable-size tuple. In combination with macros PyTuple_SET_ITEM it can be use3d as more verbose but slightly more efficient version of PyTuple_Pack. But PyTuple_SET_ITEM is not in the limited API. For your case I suggest to use PyTuple_Pack (unless you find that PyTuple_New+PyTuple_SET_ITEM is critically more performant). -- https://mail.python.org/mailman/listinfo/python-list
