fromnumeric.py 文件源码

def alen(a):
    """
    Return the length of the first dimension of the input array.

    Parameters
    ----------
    a : array_like
       Input array.

    Returns
    -------
    alen : int
       Length of the first dimension of `a`.

    See Also
    --------
    shape, size

    Examples
    --------
    >>> a = np.zeros((7,4,5))
    >>> a.shape[0]
    7
    >>> np.alen(a)
    7

    """
    try:
        return len(a)
    except TypeError:
        return len(array(a, ndmin=1))