Caveats ======= Since Cython mixes C and Python semantics, some things may be a bit surprising or unintuitive. Work always goes on to make Cython more natural for Python users, so this list may change in the future. - Given two typed ``int`` variables ``a`` and ``b``, ``a % b`` has the same sign as the second argument (following Python semantics) rather than having the same sign as the first (as in C). The C behavior can be obtained, at some speed gain, by enabling the cdivision directive (versions prior to Cython 0.12 always followed C semantics). - Care is needed with unsigned types. ``cdef unsigned n = 10; print(range(-n, n))`` will print an empty list, since ``-n`` wraps around to a large positive integer prior to being passed to the ``range`` function. - Python's ``float`` type actually wraps C ``double`` values, and the ``int`` type in Python 2.x wraps C ``long`` values.