basic.py 文件源码

def as_scalar(x, name=None):
    from ..tensor import TensorType, scalar_from_tensor
    if isinstance(x, gof.Apply):
        if len(x.outputs) != 1:
            raise ValueError("It is ambiguous which output of a multi-output"
                             " Op has to be fetched.", x)
        else:
            x = x.outputs[0]
    if isinstance(x, Variable):
        if isinstance(x.type, Scalar):
            return x
        elif isinstance(x.type, TensorType) and x.ndim == 0:
            return scalar_from_tensor(x)
        else:
            raise TypeError("Variable type field must be a Scalar.", x, x.type)
    try:
        return constant(x)
    except TypeError:
        raise TypeError("Cannot convert %s to Scalar" % x, type(x))