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`adapt` -- Types adaptation

docs/api/adapt.rst

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adapt -- Types adaptation

.. module:: psycopg.adapt

The !psycopg.adapt module exposes a set of objects useful for the configuration of data adaptation, which is the conversion of Python objects to PostgreSQL data types and back.

These objects are useful if you need to configure data adaptation, i.e. if you need to change the default way that Psycopg converts between types or if you want to adapt custom data types and objects. You don't need this object in the normal use of Psycopg.

See :ref:adaptation for an overview of the Psycopg adaptation system.

.. _abstract base class: https://docs.python.org/glossary.html#term-abstract-base-class

Dumpers and loaders

.. autoclass:: Dumper(cls, context=None)

This is an `abstract base class`_, partially implementing the
`~psycopg.abc.Dumper` protocol. Subclasses *must* at least implement the
`.dump()` method and optionally override other members.

.. automethod:: dump

    .. versionchanged:: 3.2

        `!dump()` can also return `!None`, to represent a :sql:`NULL` in
        the database.

.. attribute:: format
    :type: psycopg.pq.Format
    :value: TEXT

    Class attribute. Set it to `~psycopg.pq.Format.BINARY` if the class
    `dump()` methods converts the object to binary format.

.. automethod:: quote

.. automethod:: get_key

.. automethod:: upgrade

.. autoclass:: Loader(oid, context=None)

This is an `abstract base class`_, partially implementing the
`~psycopg.abc.Loader` protocol. Subclasses *must* at least implement the
`.load()` method and optionally override other members.

.. automethod:: load

.. attribute:: format
    :type: psycopg.pq.Format
    :value: TEXT

    Class attribute. Set it to `~psycopg.pq.Format.BINARY` if the class
    `load()` methods converts the object from binary format.

Other objects used in adaptations

.. autoclass:: PyFormat :members:

.. autoclass:: AdaptersMap

.. seealso:: :ref:adaptation for an explanation about how contexts are connected.

.. automethod:: register_dumper .. automethod:: register_loader

.. attribute:: types

   The object where to look up for types information (such as the mapping
   between type names and oids in the specified context).

   :type: `~psycopg.types.TypesRegistry`

.. automethod:: get_dumper .. automethod:: get_dumper_by_oid .. automethod:: get_loader

.. autoclass:: Transformer(context=None)

:param context: The context where the transformer should operate.
:type context: `~psycopg.abc.AdaptContext`