def load_cls(cls_item, prefix=None):
    path = None
    if isinstance(cls_item, basestring):
        (path, cls_name) = cls_item.split(':')[:2]
    elif isinstance(cls_item, tuple):
        (path, cls_name) = cls_item
    if path is not None:
        try:
            module = __import__(path, globals(), locals(), [cls_name])
        except __HOLE__:
            if prefix is None:
                raise
            path = '.'.join([prefix, path])
            module = __import__(path, globals(), locals(), [cls_name])
        return getattr(module, cls_name)
    return cls_item
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/modules/utils.py/load_cls