Class Description

tables/description.py:330–803

This class represents descriptions of the structure of tables. An instance of this class is automatically bound to Table (see :ref:`TableClassDescr`) objects when they are created. It provides a browseable representation of the structure of the table, made of non-nested (Col - see

# Table description classes
# =========================
class Description:
    """This class represents descriptions of the structure of tables.

    An instance of this class is automatically bound to Table (see
    :ref:`TableClassDescr`) objects when they are created.  It provides a
    browseable representation of the structure of the table, made of non-nested
    (Col - see :ref:`ColClassDescr`) and nested (Description) columns.

    Column definitions under a description can be accessed as attributes of it
    (*natural naming*). For instance, if table.description is a Description
    instance with a column named col1 under it, the later can be accessed as
    table.description.col1. If col1 is nested and contains a col2 column, this
    can be accessed as table.description.col1.col2. Because of natural naming,
    the names of members start with special prefixes, like in the Group class
    (see :ref:`GroupClassDescr`).

    .. rubric:: Description attributes

    .. attribute:: _v_colobjects

        A dictionary mapping the names of the columns hanging
        directly from the associated table or nested column to their
        respective descriptions (Col - see :ref:`ColClassDescr` or
        Description - see :ref:`DescriptionClassDescr` instances).

        .. versionchanged:: 3.0
           The *_v_colObjects* attribute has been renamed into
           *_v_colobjects*.

    .. attribute:: _v_dflts

        A dictionary mapping the names of non-nested columns
        hanging directly from the associated table or nested column
        to their respective default values.

    .. attribute:: _v_dtype

        The NumPy type which reflects the structure of this
        table or nested column.  You can use this as the
        dtype argument of NumPy array factories.

    .. attribute:: _v_dtypes

        A dictionary mapping the names of non-nested columns
        hanging directly from the associated table or nested column
        to their respective NumPy types.

    .. attribute:: _v_is_nested

        Whether the associated table or nested column contains
        further nested columns or not.

    .. attribute:: _v_itemsize

        The size in bytes of an item in this table or nested column.

    .. attribute:: _v_name