any non-float non-integer argument is now converted to an integer (if possible) using its __int__ method. Previously, only small arguments were treated this way; larger arguments (those whose __int__ was outside the range of a C long) would produce a TypeError. Patch by Alexander Belopolsky (with minor modifications).
in a Py_ssize_t, not an int.
string <-> float conversions; this makes sure that the result of the round operation is correctly rounded, and hence displays nicely using the new float repr.