in or `vardict` is None then returns
    NumPy arrays in the globals() dictionary (all NumPy arrays in the
    namespace).

    Parameters
    ----------
    vardict : dict, optional
        A dictionary possibly containing ndarrays.  Default is globals().

    Returns
    -------
    out : None
        Returns 'None'.

    Notes
    -----
    Prints out the name, shape, bytes and type of all of the ndarrays
    present in `vardict`.

    Examples
    --------
    >>> a = np.arange(10)
    >>> b = np.ones(20)
    >>> np.who()
    Name            Shape            Bytes            Type
    ===========================================================
    a               10               80               int64
    b               20               160              float64
    Upper bound on total bytes  =       240

    >>> d = {'x': np.arange(2.0), 'y': np.arange(3.0), 'txt': 'Some str',
    ... 'idx':5}
    >>> np.who(d)
    Name            Shape            Bytes            Type
    ===========================================================
    x               2                16               float64
    y               3                24               float64
    Upper bound on total bytes  =       40

    Nz