Class recarray

numpy/core/records.py:308–573

Construct an ndarray that allows field access using attributes. Arrays may have a data-types containing fields, analogous to columns in a spread sheet. An example is ``[(x, int), (y, float)]``, where each entry in the array is a pair of ``(int, float)``. Normally, these attributes

#  the fields (and any subfields)

class recarray(ndarray):
    """Construct an ndarray that allows field access using attributes.

    Arrays may have a data-types containing fields, analogous
    to columns in a spread sheet.  An example is ``[(x, int), (y, float)]``,
    where each entry in the array is a pair of ``(int, float)``.  Normally,
    these attributes are accessed using dictionary lookups such as ``arr['x']``
    and ``arr['y']``.  Record arrays allow the fields to be accessed as members
    of the array, using ``arr.x`` and ``arr.y``.

    Parameters
    ----------
    shape : tuple
        Shape of output array.
    dtype : data-type, optional
        The desired data-type.  By default, the data-type is determined
        from `formats`, `names`, `titles`, `aligned` and `byteorder`.
    formats : list of data-types, optional
        A list containing the data-types for the different columns, e.g.
        ``['i4', 'f8', 'i4']``.  `formats` does *not* support the new
        convention of using types directly, i.e. ``(int, float, int)``.
        Note that `formats` must be a list, not a tuple.
        Given that `formats` is somewhat limited, we recommend specifying
        `dtype` instead.
    names : tuple of str, optional
        The name of each column, e.g. ``('x', 'y', 'z')``.
    buf : buffer, optional
        By default, a new array is created of the given shape and data-type.
        If `buf` is specified and is an object exposing the buffer interface,
        the array will use the memory from the existing buffer.  In this case,
        the `offset` and `strides` keywords are available.

    Other Parameters
    ----------------
    titles : tuple of str, optional
        Aliases for column names.  For example, if `names` were
        ``('x', 'y', 'z')`` and `titles` is
        ``('x_coordinate', 'y_coordinate', 'z_coordinate')``, then
        ``arr['x']`` is equivalent to both ``arr.x`` and ``arr.x_coordinate``.
    byteorder : {'<', '>', '='}, optional
        Byte-order for all fields.
    aligned : bool, optional
        Align the fields in memory as the C-compiler would.
    strides : tuple of ints, optional
        Buffer (`buf`) is interpreted according to these strides (strides
        define how many bytes each array element, row, column, etc.
        occupy in memory).
    offset : int, optional
        Start reading buffer (`buf`) from this offset onwards.
    order : {'C', 'F'}, optional
        Row-major (C-style) or column-major (Fortran-style) order.

    Returns
    -------
    rec : recarray
        Empty array of the given shape and type.

    See Also