The !psycopg module

Psycopg implements the Python Database DB API 2.0 specification. As such it also exposes the module-level objects required by the specifications.

.. __: https://www.python.org/dev/peps/pep-0249/ .. __: https://www.python.org/dev/peps/pep-0249/#module-interface

.. module:: psycopg

.. autofunction:: connect

This is an alias of the class method Connection.connect: see its documentation for details.

If you need an asynchronous connection use AsyncConnection.connect instead.

.. data:: capabilities

An object that can be used to verify that the client library used by
psycopg implements a certain feature. For instance::

    # Fail at import time if encrypted passwords is not available
    import psycopg
    psycopg.capabilities.has_encrypt_password(check=True)

    # Verify at runtime if a feature can be used
    if psycopg.capabilities.has_hostaddr():
        print(conn.info.hostaddr)
    else:
        print("unknown connection hostadd")

:type: `Capabilities`

.. versionadded:: 3.2

.. rubric:: Exceptions

The standard DBAPI exceptions__ are exposed both by the !psycopg module and by the psycopg.errors module. The latter also exposes more specific exceptions, mapping to the database error states (see :ref:sqlstate-exceptions).

.. __: https://www.python.org/dev/peps/pep-0249/#exceptions

.. parsed-literal::

`!Exception`
\|__ `Warning`
\|__ `Error`
    \|__ `InterfaceError`
    \|__ `DatabaseError`
        \|__ `DataError`
        \|__ `OperationalError`
        \|__ `IntegrityError`
        \|__ `InternalError`
        \|__ `ProgrammingError`
        \|__ `NotSupportedError`

.. data:: adapters

The default adapters map establishing how Python and PostgreSQL types are converted into each other.

This map is used as a template when new connections are created, using psycopg.connect(). Its ~psycopg.adapt.AdaptersMap.types attribute is a ~psycopg.types.TypesRegistry containing information about every PostgreSQL builtin type, useful for adaptation customisation (see :ref:adaptation)::

   >>> psycopg.adapters.types["int4"]
   <TypeInfo: int4 (oid: 23, array oid: 1007)>

:type: ~psycopg.adapt.AdaptersMap