converters.py 文件源码

def Instance2Str(o, d):

    """

    Convert an Instance to a string representation.  If the __str__()
    method produces acceptable output, then you don't need to add the
    class to conversions; it will be handled by the default
    converter. If the exact class is not found in d, it will use the
    first class it can find for which o is an instance.

    """

    if d.has_key(o.__class__):
        return d[o.__class__](o, d)
    cl = filter(lambda x,o=o:
                type(x) is types.ClassType
                and isinstance(o, x), d.keys())
    if not cl and hasattr(types, 'ObjectType'):
        cl = filter(lambda x,o=o:
                    type(x) is types.TypeType
                    and isinstance(o, x)
                    and d[x] is not Instance2Str,
                    d.keys())
    if not cl:
        return d[types.StringType](o,d)
    d[o.__class__] = d[cl[0]]
    return d[cl[0]](o, d)