[Devin Jeanpierre <jeanpierr...@gmail.com>] > PyPy (5.8): > >>>> x = 1e300 > >>>> x.is_integer() > True > >>>> math.sqrt(x**2).is_integer() > False > >>>> x**2 > inf
I think you missed that David said "even without reaching inf" (you did reach inf), and that I said "such that x*x neither overflows nor underflows". Those are technical words related to IEEE-754: your x*x sets the IEEE overflow flag, although CPython may or may not raise the Python OverflowError exception. > > (It gives an OverflowError on my CPython installs.) > > I believe this is allowed, and Python is not required to raise > OverflowError here: > https://docs.python.org/3.6/library/exceptions.html#OverflowError > says: > >> for historical reasons, OverflowError is sometimes raised for integers that >> are outside a required range. Because of the lack of standardization of >> floating point exception handling in C, most floating point operations are >> not checked You can avoid the OverflowError (but not the IEEE overflow condition!) under CPython by multiplying instead: >>> x = 1e300 >>> x*x inf _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
