input_validation.py 文件源码

def expect_dimensions(**dimensions):
    """
    Preprocessing decorator that verifies inputs are numpy arrays with a
    specific dimensionality.

    Usage
    -----
    >>> from numpy import array
    >>> @expect_dimensions(x=1, y=2)
    ... def foo(x, y):
    ...    return x[0] + y[0, 0]
    ...
    >>> foo(array([1, 1]), array([[1, 1], [2, 2]]))
    2
    >>> foo(array([1, 1], array([1, 1])))
    Traceback (most recent call last):
       ...
    TypeError: foo() expected a 2-D array for argument 'y', but got a 1-D array instead.  # noqa
    """
    def _expect_dimension(expected_ndim):
        def _check(func, argname, argvalue):
            funcname = _qualified_name(func)
            actual_ndim = argvalue.ndim
            if actual_ndim != expected_ndim:
                if actual_ndim == 0:
                    actual_repr = 'scalar'
                else:
                    actual_repr = "%d-D array" % actual_ndim
                raise ValueError(
                    "{func}() expected a {expected:d}-D array"
                    " for argument {argname!r}, but got a {actual}"
                    " instead.".format(
                        func=funcname,
                        expected=expected_ndim,
                        argname=argname,
                        actual=actual_repr,
                    )
                )
            return argvalue
        return _check
    return preprocess(**valmap(_expect_dimension, dimensions))