import sys

PY2 = sys.version_info[0] < 3
PY3 = sys.version_info[0] >= 3

PYXY = tuple(sys.version_info[:2])

if PY3:
    import builtins
    exec_ = getattr(builtins, "exec")
    del builtins

else:
    def exec_(_code_, _globs_=None, _locs_=None):
        """Execute code in a namespace."""
        if _globs_ is None:
            frame = sys._getframe(1)
            _globs_ = frame.f_globals
            if _locs_ is None:
                _locs_ = frame.f_locals
            del frame
        elif _locs_ is None:
            _locs_ = _globs_
        exec("""exec _code_ in _globs_, _locs_""")

    exec_("""def reraise(tp, value, tb=None):
    raise tp, value, tb
""")

try:
    from inspect import getfullargspec
except ImportError:
    from inspect import getargspec as getfullargspec