who can tell me what can call the built-in functions in next code

i know some of this开发者_C百科,ex.

__mod__ will be call /

__eq__will be call == > and <

but i don't know all.

    def __nonzero__(self):
        # an image is "true" if it contains at least one non-zero pixel
        return self.im.getbbox() is not None
    def __abs__(self):
        return self.apply("abs", self)
    def __pos__(self):
        return self
    def __neg__(self):
        return self.apply("neg", self)

    # binary operators
    def __add__(self, other):
        return self.apply("add", self, other)
    def __radd__(self, other):
        return self.apply("add", other, self)
    def __sub__(self, other):
        return self.apply("sub", self, other)
    def __rsub__(self, other):
        return self.apply("sub", other, self)
    def __mul__(self, other):
        return self.apply("mul", self, other)
    def __rmul__(self, other):
        return self.apply("mul", other, self)
    def __div__(self, other):
        return self.apply("div", self, other)
    def __rdiv__(self, other):
        return self.apply("div", other, self)
    def __mod__(self, other):
        return self.apply("mod", self, other)
    def __rmod__(self, other):
        return self.apply("mod", other, self)
    def __pow__(self, other):
        return self.apply("pow", self, other)
    def __rpow__(self, other):
        return self.apply("pow", other, self)

    # bitwise
    def __invert__(self):
        return self.apply("invert", self)
    def __and__(self, other):
        return self.apply("and", self, other)
    def __rand__(self, other):
        return self.apply("and", other, self)
    def __or__(self, other):
        return self.apply("or", self, other)
    def __ror__(self, other):
        return self.apply("or", other, self)
    def __xor__(self, other):
        return self.apply("xor", self, other)
    def __rxor__(self, other):
        return self.apply("xor", other, self)
    def __lshift__(self, other):
        return self.apply("lshift", self, other)
    def __rshift__(self, other):
        return self.apply("rshift", self, other)

    # logical
    def __eq__(self, other):
        return self.apply("eq", self, other)
    def __ne__(self, other):
        return self.apply("ne", self, other)
    def __lt__(self, other):
        return self.apply("lt", self, other)
    def __le__(self, other):
        return self.apply("le", self, other)
    def __gt__(self, other):
        return self.apply("gt", self, other)
    def __ge__(self, other):
        return self.apply("ge", self, other)

Section 3.4 of the Python Language Reference covers the magic methods.

See the Special Method Names section in the reference manual, including Basic Customization and Emulating Numeric Types.

__mod__ is called for %, not for / as you state:

>>> class x(int):
...   def __mod__(self, y):
...     print '__mod__(%s, %s)' % (self, y)
...     return int.__mod__(self, y)
... 
>>> a = x(23)
>>> a / 4
5
>>> a % 4
__mod__(23, 4)
3
>>> 

Make and use similar toy classes to clarify any doubt you may have about a special method, if any are left after you read the docs.