Release notes

Current release

What’s new in psycopg 2.9.9

  • Add support for Python 3.12.

  • Drop support for Python 3.6.

What’s new in psycopg 2.9.8

  • Wheel package bundled with PostgreSQL 16 libpq in order to add support for recent features, such as sslcertmode.

What’s new in psycopg 2.9.7

  • Fix propagation of exceptions raised during module initialization (ticket #1598).

  • Fix building when pg_config returns an empty string (ticket #1599).

  • Wheel package bundled with OpenSSL 1.1.1v.

What’s new in psycopg 2.9.6

  • Package manylinux 2014 for aarch64 and ppc64le platforms, in order to include libpq 15 in the binary package (ticket #1396).

  • Wheel package bundled with OpenSSL 1.1.1t.

What’s new in psycopg 2.9.5

  • Add support for Python 3.11.

  • Add support for rowcount in MERGE statements in binary packages (ticket #1497).

  • Wheel package bundled with OpenSSL 1.1.1r and PostgreSQL 15 libpq.

What’s new in psycopg 2.9.4

  • Fix register_composite(), register_range() with customized search_path (ticket #1487).

  • Handle correctly composite types with names or in schemas requiring escape.

  • Find pg_service.conf file in the /etc/postgresql-common directory in binary packages (ticket #1365).

  • errorcodes map and errors classes updated to PostgreSQL 15.

  • Wheel package bundled with OpenSSL 1.1.1q and PostgreSQL 14.4 libpq.

What’s new in psycopg 2.9.3

  • Alpine (musl) wheels now available (ticket #1392).

  • macOS arm64 (Apple M1) wheels now available (ticket 1482).

What’s new in psycopg 2.9.2

  • Raise ValueError for dates >= Y10k (ticket #1307).

  • errorcodes map and errors classes updated to PostgreSQL 14.

  • Add preliminary support for Python 3.11 (tickets #1376, #1386).

  • Wheel package bundled with OpenSSL 1.1.1l and PostgreSQL 14.1 libpq (ticket #1388).

What’s new in psycopg 2.9.1

What’s new in psycopg 2.9

  • with connection starts a transaction on autocommit transactions too (ticket #941).

  • Timezones with fractional minutes are supported on Python 3.7 and following (ticket #1272).

  • Escape table and column names in copy_from() and copy_to().

  • Connection exceptions with sqlstate 08XXX reclassified as OperationalError (a subclass of the previously used DatabaseError) (ticket #1148).

  • Include library dirs required from libpq to work around MacOS build problems (ticket #1200).

Other changes:

  • Dropped support for Python 2.7, 3.4, 3.5 (tickets #1198, #1000, #1197).

  • Dropped support for mx.DateTime.

  • Use datetime.timezone objects by default in datetime objects instead of FixedOffsetTimezone.

  • The module is deprecated and scheduled to be dropped in the next major release.

  • Provide PEP 599 wheels packages (manylinux2014 tag) for i686 and x86_64 platforms.

  • Provide PEP 600 wheels packages (manylinux_2_24 tag) for aarch64 and ppc64le platforms.

  • Wheel package bundled with OpenSSL 1.1.1k and PostgreSQL 13.3 libpq.

  • Build system for Linux/MacOS binary packages moved to GitHub Actions.

What’s new in psycopg 2.8.7

  • Accept empty params as connect() (ticket #1250).

  • Fix attributes refcount in Column initialisation (ticket #1252).

  • Allow re-initialisation of static variables in the C module (ticket #1267).

What’s new in psycopg 2.8.6

  • Fixed memory leak changing connection encoding to the current one (ticket #1101).

  • Fixed search of mxDateTime headers in virtualenvs (ticket #996).

  • Added missing values from errorcodes (ticket #1133).

  • cursor.query reports the query of the last COPY operation too (ticket #1141).

  • errorcodes map and errors classes updated to PostgreSQL 13.

  • Added wheel packages for ARM architecture (ticket #1125).

  • Wheel package bundled with OpenSSL 1.1.1g.

What’s new in psycopg 2.8.5

What’s new in psycopg 2.8.4

  • Fixed building with Python 3.8 (ticket #854).

  • Don’t swallow keyboard interrupts on connect when a password is specified in the connection string (ticket #898).

  • Don’t advance replication cursor when the message wasn’t confirmed (ticket #940).

  • Fixed inclusion of time.h on linux (ticket #951).

  • Fixed int overflow for large values in table_oid and type_code (ticket #961).

  • errorcodes map and errors classes updated to PostgreSQL 12.

  • Wheel package bundled with OpenSSL 1.1.1d and PostgreSQL at least 11.4.

What’s new in psycopg 2.8.3

  • Added interval_status parameter to start_replication() method and other facilities to send automatic replication keepalives at periodic intervals (ticket #913).

  • Fixed namedtuples caching introduced in 2.8 (ticket #928).

What’s new in psycopg 2.8.2

  • Fixed RealDictCursor when there are repeated columns (ticket #884).

  • Binary packages built with openssl 1.1.1b. Should fix concurrency problems (tickets #543, #836).

What’s new in psycopg 2.8.1

  • Fixed RealDictRow modifiability (ticket #886).

  • Fixed “there’s no async cursor” error polling a connection with no cursor (ticket #887).

What’s new in psycopg 2.8

New features:

Bug fixes:

  • Fixed connections occasionally broken by the unrelated use of the multiprocessing module (ticket #829).

  • Fixed async communication blocking if results are returned in different chunks, e.g. with notices interspersed to the results (ticket #856).

  • Fixed adaptation of numeric subclasses such as IntEnum (ticket #591).

Other changes:

  • Dropped support for Python 2.6, 3.2, 3.3.

  • Dropped psycopg1 module.

  • Dropped deprecated register_tstz_w_secs() (was previously a no-op).

  • Dropped deprecated PersistentConnectionPool. This pool class was mostly designed to interact with Zope. Use ZPsycopgDA.pool instead.

  • Binary packages no longer installed by default. The ‘psycopg2-binary’ package must be used explicitly.

  • Dropped PSYCOPG_DISPLAY_SIZE build parameter.

  • Dropped support for mxDateTime as the default date and time adapter. mxDatetime support continues to be available as an alternative to Python’s builtin datetime.

  • No longer use 2to3 during installation for Python 2 & 3 compatibility. All source files are now compatible with Python 2 & 3 as is.

  • The psycopg2.test package is no longer installed by python install.

  • Wheel package bundled with OpenSSL 1.0.2r and PostgreSQL 11.2 libpq.

What’s new in psycopg 2.7.7

  • Cleanup of the cursor results assignment code, which might have solved double free and inconsistencies in concurrent usage (tickets #346, #384).

  • Wheel package bundled with OpenSSL 1.0.2q.

What’s new in psycopg

  • Fixed binary package broken on OS X 10.12 (ticket #807).

  • Wheel package bundled with PostgreSQL 11.1 libpq.

What’s new in psycopg 2.7.6

  • Close named cursors if exist, even if execute() wasn’t called (ticket #746).

  • Fixed building on modern FreeBSD versions with Python 3.7 (ticket #755).

  • Fixed hang trying to COPY via execute() in asynchronous connections (ticket #781).

  • Fixed adaptation of arrays of empty arrays (ticket #788).

  • Fixed segfault accessing the connection’s readonly and deferrable attributes repeatedly (ticket #790).

  • execute_values() accepts Composable objects (ticket #794).

  • errorcodes map updated to PostgreSQL 11.

  • Wheel package bundled with PostgreSQL 10.5 libpq and OpenSSL 1.0.2p.

What’s new in psycopg 2.7.5

  • Allow non-ascii chars in namedtuple fields (regression introduced fixing ticket #211).

  • Fixed adaptation of arrays of arrays of nulls (ticket #325).

  • Fixed building on Solaris 11 and derivatives such as SmartOS and illumos (ticket #677).

  • Maybe fixed building on MSYS2 (as reported in ticket #658).

  • Allow string subclasses in connection and other places (ticket #679).

  • Don’t raise an exception closing an unused named cursor (ticket #716).

  • Wheel package bundled with PostgreSQL 10.4 libpq and OpenSSL 1.0.2o.

What’s new in psycopg 2.7.4

  • Moving away from installing the wheel package by default. Packages installed from wheel raise a warning on import. Added package psycopg2-binary to install from wheel instead (ticket #543).

  • Convert fields names into valid Python identifiers in NamedTupleCursor (ticket #211).

  • Fixed Solaris 10 support (ticket #532).

  • cursor.mogrify() can be called on closed cursors (ticket #579).

  • Fixed setting session characteristics in corner cases on autocommit connections (ticket #580).

  • Fixed MinTimeLoggingCursor on Python 3 (ticket #609).

  • Fixed parsing of array of points as floats (ticket #613).

  • Fixed __libpq_version__ building with libpq >= 10.1 (ticket #632).

  • Fixed rowcount after executemany() with RETURNING statements (ticket #633).

  • Fixed compatibility problem with pypy3 (ticket #649).

  • Wheel packages bundled with PostgreSQL 10.1 libpq and OpenSSL 1.0.2n.

  • Wheel packages for Python 2.6 no more available (support dropped from wheel building infrastructure).

What’s new in psycopg

  • Wheel package bundled with PostgreSQL 10.0 libpq and OpenSSL 1.0.2l (tickets #601, #602).

What’s new in psycopg

  • Dropped libresolv from wheel package to avoid incompatibility with glibc 2.26 (wheels ticket #2).

What’s new in psycopg 2.7.3

  • Restored default timestamptz[] typecasting to Python datetime. Regression introduced in Psycopg 2.7.2 (ticket #578).

What’s new in psycopg 2.7.2

  • Fixed inconsistent state in externally closed connections (tickets #263, #311, #443). Was fixed in 2.6.2 but not included in 2.7 by mistake.

  • Fixed Python exceptions propagation in green callback (ticket #410).

  • Don’t display the password in connection.dsn when the connection string is specified as an URI (ticket #528).

  • Return objects with timezone parsing “infinity” timestamptz (ticket #536).

  • Dropped dependency on VC9 runtime on Windows binary packages (ticket #541).

  • Fixed segfault in lobject() when mode=None (ticket #544).

  • Fixed lobject() keyword argument lobject_factory (ticket #545).

  • Fixed consume_stream() keepalive_interval argument (ticket #547).

  • Maybe fixed random import error on Python 3.6 in multiprocess environment (ticket #550).

  • Fixed random SystemError upon receiving abort signal (ticket #551).

  • Accept Composable objects in start_replication_expert() (ticket #554).

  • Parse intervals returned as microseconds from Redshift (ticket #558).

  • Added Json prepare() method to consider connection params when adapting (ticket #562).

  • errorcodes map updated to PostgreSQL 10 beta 1.

What’s new in psycopg 2.7.1

  • Ignore None arguments passed to connect() and make_dsn() (ticket #517).

  • OpenSSL upgraded from major version 0.9.8 to 1.0.2 in the Linux wheel packages (ticket #518).

  • Fixed build with libpq versions < 9.3 (ticket #520).

What’s new in psycopg 2.7

New features:

  • Added sql module to generate SQL dynamically (ticket #308).

  • Added Replication protocol support (ticket #322). Main authors are Oleksandr Shulgin and Craig Ringer, who deserve a huge thank you.

  • Added parse_dsn() and make_dsn() functions (tickets #321, #363). connect() now can take both dsn and keyword arguments, merging them together.

  • Added __libpq_version__ and libpq_version() to inspect the version of the libpq library the module was bundled with (tickets #35, #323).

  • The attributes notices and notifies can be customized replacing them with any object exposing an append() method (ticket #326).

  • Adapt network types to ipaddress objects when available. When not enabled, convert arrays of network types to lists by default. The old Inet adapter is deprecated (tickets #317, #343, #387).

  • Added quote_ident() function (ticket #359).

  • Added get_dsn_parameters() connection method (ticket #364).

  • callproc() now accepts a dictionary of parameters (ticket #381).

  • Give precedence to __conform__() over superclasses to choose an object adapter (ticket #456).

  • Using Python C API decoding functions and codecs caching for faster unicode encoding/decoding (ticket #473).

  • executemany() slowness addressed by execute_batch() and execute_values() (ticket #491).

  • Added async_ as an alias for async to support Python 3.7 where async will become a keyword (ticket #495).

  • Unless in autocommit, do not use default_transaction_* settings to control the session characteristics as it may create problems with external connection pools such as pgbouncer; use BEGIN options instead (ticket #503).

  • isolation_level is now writable and entirely separated from autocommit; added readonly, deferrable writable attributes.

Bug fixes:

  • Throw an exception trying to pass NULL chars as parameters (ticket #420).

  • Fixed error caused by missing decoding LoggingConnection (ticket #483).

  • Fixed integer overflow in interval seconds (ticket #512).

  • Make Range objects picklable (ticket #462).

  • Fixed version parsing and building with PostgreSQL 10 (ticket #489).

Other changes:

  • Dropped support for Python 2.5 and 3.1.

  • Dropped support for client library older than PostgreSQL 9.1 (but older server versions are still supported).

  • isolation_level doesn’t read from the database but will return ISOLATION_LEVEL_DEFAULT if no value was set on the connection.

  • Empty arrays no more converted into lists if they don’t have a type attached (ticket #506)

What’s new in psycopg 2.6.2

  • Fixed inconsistent state in externally closed connections (tickets #263, #311, #443).

  • Report the server response status on errors (such as ticket #281).

  • Raise NotSupportedError on unhandled server response status (ticket #352).

  • Allow overriding string adapter encoding with no connection (ticket #331).

  • The wait_select callback allows interrupting a long-running query in an interactive shell using Ctrl-C (ticket #333).

  • Fixed PersistentConnectionPool on Python 3 (ticket #348).

  • Fixed segfault on repr() of an unitialized connection (ticket #361).

  • Allow adapting bytes using QuotedString on Python 3 (ticket #365).

  • Added support for setuptools/wheel (ticket #370).

  • Fix build on Windows with Python 3.5, VS 2015 (ticket #380).

  • Fixed errorcodes.lookup initialization thread-safety (ticket #382).

  • Fixed read() exception propagation in copy_from (ticket #412).

  • Fixed possible NULL TZ decref (ticket #424).

  • errorcodes map updated to PostgreSQL 9.5.

What’s new in psycopg 2.6.1

  • Lists consisting of only None are escaped correctly (ticket #285).

  • Fixed deadlock in multithread programs using OpenSSL (ticket #290).

  • Correctly unlock the connection after error in flush (ticket #294).

  • Fixed MinTimeLoggingCursor.callproc() (ticket #309).

  • Added support for MSVC 2015 compiler (ticket #350).

What’s new in psycopg 2.6

New features:

  • Added support for large objects larger than 2GB. Many thanks to Blake Rouse and the MAAS Team for the feature development.

  • Python time objects with a tzinfo specified and PostgreSQL timetz data are converted into each other (ticket #272).

Bug fixes:

  • Json adapter’s str() returns the adapted content instead of the repr() (ticket #191).

What’s new in psycopg 2.5.5

  • Named cursors used as context manager don’t swallow the exception on exit (ticket #262).

  • cursor.description can be pickled (ticket #265).

  • Propagate read error messages in COPY FROM (ticket #270).

  • PostgreSQL time 24:00 is converted to Python 00:00 (ticket #278).

What’s new in psycopg 2.5.4

  • Added jsonb support for PostgreSQL 9.4 (ticket #226).

  • Fixed segfault if COPY statements are passed to execute() instead of using the proper methods (ticket #219).

  • Force conversion of pool arguments to integer to avoid potentially unbounded pools (ticket #220).

  • Cursors WITH HOLD don’t begin a new transaction upon move/fetch/close (ticket #228).

  • Cursors WITH HOLD can be used in autocommit (ticket #229).

  • callproc() doesn’t silently ignore an argument without a length.

  • Fixed memory leak with large objects (ticket #256).

  • Make sure the internal module can be imported stand-alone (to allow modules juggling such as the one described in ticket #201).

What’s new in psycopg 2.5.3

  • Work around pip issue #1630 making installation via pip -e git+url impossible (ticket #18).

  • Copy operations correctly set the cursor.rowcount attribute (ticket #180).

  • It is now possible to call get_transaction_status() on closed connections.

  • Fixed unsafe access to object names causing assertion failures in Python 3 debug builds (ticket #188).

  • Mark the connection closed if found broken on poll() (from ticket #192 discussion)

  • Fixed handling of dsn and closed attributes in connection subclasses failing to connect (from ticket #192 discussion).

  • Added arbitrary but stable order to Range objects, thanks to Chris Withers (ticket #193).

  • Avoid blocking async connections on connect (ticket #194). Thanks to Adam Petrovich for the bug report and diagnosis.

  • Don’t segfault using poorly defined cursor subclasses which forgot to call the superclass init (ticket #195).

  • Mark the connection closed when a Socket connection is broken, as it happens for TCP connections instead (ticket #196).

  • Fixed overflow opening a lobject with an oid not fitting in a signed int (ticket #203).

  • Fixed handling of explicit default cursor_factory=None in connection.cursor() (ticket #210).

  • Fixed possible segfault in named cursors creation.

  • Fixed debug build on Windows, thanks to James Emerton.

What’s new in psycopg 2.5.2

  • Fixed segfault pickling the exception raised on connection error (ticket #170).

  • Meaningful connection errors report a meaningful message, thanks to Alexey Borzenkov (ticket #173).

  • Manually creating lobject with the wrong parameter doesn’t segfault (ticket #187).

What’s new in psycopg 2.5.1

  • Fixed build on Solaris 10 and 11 where the round() function is already declared (ticket #146).

  • Fixed comparison of Range with non-range objects (ticket #164). Thanks to Chris Withers for the patch.

  • Fixed double-free on connection dealloc (ticket #166). Thanks to Gangadharan S.A. for the report and fix suggestion.

What’s new in psycopg 2.5

New features:

Bug fixes:

  • Properly cleanup memory of broken connections (ticket #148).

  • Fixed bad interaction of with other dependencies in Distribute projects on Python 3 (ticket #153).

Other changes:

  • Added support for Python 3.3.

  • Dropped support for Python 2.4. Please use Psycopg 2.4.x if you need it.

  • errorcodes map updated to PostgreSQL 9.2.

  • Dropped Zope adapter from source repository. ZPsycopgDA now has its own project at <>.

What’s new in psycopg 2.4.6

  • Fixed ‘cursor()’ arguments propagation in connection subclasses and overriding of the ‘cursor_factory’ argument. Thanks to Corry Haines for the report and the initial patch (ticket #105).

  • Dropped GIL release during string adaptation around a function call invoking a Python API function, which could cause interpreter crash. Thanks to Manu Cupcic for the report (ticket #110).

  • Close a green connection if there is an error in the callback. Maybe a harsh solution but it leaves the program responsive (ticket #113).

  • ‘register_hstore()’, ‘register_composite()’, ‘tpc_recover()’ work with RealDictConnection and Cursor (ticket #114).

  • Fixed broken pool for Zope and connections re-init across ZSQL methods in the same request (tickets #123, #125, #142).

  • connect() raises an exception instead of swallowing keyword arguments when a connection string is specified as well (ticket #131).

  • Discard any result produced by ‘executemany()’ (ticket #133).

  • Fixed pickling of FixedOffsetTimezone objects (ticket #135).

  • Release the GIL around PQgetResult calls after COPY (ticket #140).

  • Fixed empty strings handling in composite caster (ticket #141).

  • Fixed pickling of DictRow and RealDictRow objects.

What’s new in psycopg 2.4.5

  • The close() methods on connections and cursors don’t raise exceptions if called on already closed objects.

  • Fixed fetchmany() with no argument in cursor subclasses (ticket #84).

  • Use lo_creat() instead of lo_create() when possible for better interaction with pgpool-II (ticket #88).

  • Error and its subclasses are picklable, useful for multiprocessing interaction (ticket #90).

  • Better efficiency and formatting of timezone offset objects thanks to Menno Smits (tickets #94, #95).

  • Fixed ‘rownumber’ during iteration on cursor subclasses. Regression introduced in 2.4.4 (ticket #100).

  • Added support for ‘inet’ arrays.

  • Fixed ‘commit()’ concurrency problem (ticket #103).

  • Codebase cleaned up using the GCC Python plugin’s static analysis tool, which has revealed several unchecked return values, possible NULL dereferences, reference counting problems. Many thanks to David Malcolm for the useful tool and the assistance provided using it.

What’s new in psycopg 2.4.4

  • ‘register_composite()’ also works with the types implicitly defined after a table row, not only with the ones created by ‘CREATE TYPE’.

  • Values for the isolation level symbolic constants restored to what they were before release 2.4.2 to avoid breaking apps using the values instead of the constants.

  • Named DictCursor/RealDictCursor honour itersize (ticket #80).

  • Fixed rollback on error on Zope (ticket #73).

  • Raise ‘DatabaseError’ instead of ‘Error’ with empty libpq errors, consistently with other disconnection-related errors: regression introduced in release 2.4.1 (ticket #82).

What’s new in psycopg 2.4.3

  • connect() supports all the keyword arguments supported by the database

  • Added ‘new_array_type()’ function for easy creation of array typecasters.

  • Added support for arrays of hstores and composite types (ticket #66).

  • Fixed segfault in case of transaction started with connection lost (and possibly other events).

  • Fixed adaptation of Decimal type in sub-interpreters, such as in certain mod_wsgi configurations (ticket #52).

  • Rollback connections in transaction or in error before putting them back into a pool. Also discard broken connections (ticket #62).

  • Lazy import of the slow uuid module, thanks to Marko Kreen.

  • Fixed NamedTupleCursor.executemany() (ticket #65).

  • Fixed –static-libpq setup option (ticket #64).

  • Fixed interaction between RealDictCursor and named cursors (ticket #67).

  • Dropped limit on the columns length in COPY operations (ticket #68).

  • Fixed reference leak with arguments referenced more than once in queries (ticket #81).

  • Fixed typecasting of arrays containing consecutive backslashes.

  • ‘errorcodes’ map updated to PostgreSQL 9.1.

What’s new in psycopg 2.4.2

  • Added ‘set_session()’ method and ‘autocommit’ property to the connection. Added support for read-only sessions and, for PostgreSQL 9.1, for the “repeatable read” isolation level and the “deferrable” transaction property.

  • Psycopg doesn’t execute queries at connection time to find the default isolation level.

  • Fixed bug with multithread code potentially causing loss of sync with the server communication or lock of the client (ticket #55).

  • Don’t fail import if mx.DateTime module can’t be found, even if its support was built (ticket #53).

  • Fixed escape for negative numbers prefixed by minus operator (ticket #57).

  • Fixed refcount issue during copy. Reported and fixed by Dave Malcolm (ticket #58, Red Hat Bug 711095).

  • Trying to execute concurrent operations on the same connection through concurrent green thread results in an error instead of a deadlock.

  • Fixed detection of pg_config on Window. Report and fix, plus some long needed cleanup by Steve Lacy: thanks!

What’s new in psycopg 2.4.1

  • Use own parser for bytea output, not requiring anymore the libpq 9.0 to parse the hex format.

  • Don’t fail connection if the client encoding is a non-normalized variant. Issue reported by Peter Eisentraut.

  • Correctly detect an empty query sent to the backend (ticket #46).

  • Fixed a SystemError clobbering libpq errors raised without SQLSTATE. Bug vivisectioned by Eric Snow.

  • Fixed interaction between NamedTuple and server-side cursors.

  • Allow to specify –static-libpq on command line instead of just in ‘setup.cfg’. Patch provided by Matthew Ryan (ticket #48).

What’s new in psycopg 2.4

New features and changes:

  • Added support for Python 3.1 and 3.2. The conversion has also brought several improvements:

    • Added ‘b’ and ‘t’ mode to large objects: write can deal with both bytes strings and unicode; read can return either bytes strings or decoded unicode.

    • COPY sends Unicode data to files implementing ‘io.TextIOBase’.

    • Improved PostgreSQL-Python encodings mapping.

    • Added a few missing encodings: EUC_CN, EUC_JIS_2004, ISO885910, ISO885916, LATIN10, SHIFT_JIS_2004.

    • Dropped repeated dictionary lookups with unicode query/parameters.

  • Improvements to the named cursors:

    • More efficient iteration on named cursors, fetching ‘itersize’ records at time from the backend.

    • The named cursors name can be an invalid identifier.

  • Improvements in data handling:

    • Added ‘register_composite()’ function to cast PostgreSQL composite types into Python tuples/namedtuples.

    • Adapt types ‘bytearray’ (from Python 2.6), ‘memoryview’ (from Python 2.7) and other objects implementing the “Revised Buffer Protocol” to ‘bytea’ data type.

    • The ‘hstore’ adapter can work even when the data type is not installed in the ‘public’ namespace.

    • Raise a clean exception instead of returning bad data when receiving bytea in ‘hex’ format and the client libpq can’t parse them.

    • Empty lists correctly roundtrip Python -> PostgreSQL -> Python.

  • Other changes:

    • ‘cursor.description’ is provided as named tuples if available.

    • The build script refuses to guess values if ‘pg_config’ is not found.

    • Connections and cursors are weakly referenceable.

Bug fixes:

  • Fixed adaptation of None in composite types (ticket #26). Bug report by Karsten Hilbert.

  • Fixed several reference leaks in less common code paths.

  • Fixed segfault when a large object is closed and its connection no more available.

  • Added missing icon to ZPsycopgDA package, not available in Zope 2.12.9 (ticket #30). Bug report and patch by Pumukel.

  • Fixed conversion of negative infinity (ticket #40). Bug report and patch by Marti Raudsepp.

What’s new in psycopg 2.3.2

  • Fixed segfault with middleware not passing DateStyle to the client (ticket #24). Bug report and patch by Marti Raudsepp.

What’s new in psycopg 2.3.1

  • Fixed build problem on CentOS 5.5 x86_64 (ticket #23).

What’s new in psycopg 2.3

psycopg 2.3 aims to expose some new features introduced in PostgreSQL 9.0.

Main new features:

  • dict to hstore adapter and hstore to dict typecaster, using both 9.0 and pre-9.0 syntax.

  • Two-phase commit protocol support as per DBAPI specification.

  • Support for payload in notifications received from the backend.

  • namedtuple-returning cursor.

  • Query execution cancel.

Other features and changes:

  • Dropped support for protocol 2: Psycopg 2.3 can only connect to PostgreSQL servers with version at least 7.4.

  • Don’t issue a query at every connection to detect the client encoding and to set the datestyle to ISO if it is already compatible with what expected.

  • mogrify() now supports unicode queries.

  • Subclasses of a type that can be adapted are adapted as the superclass.

  • errorcodes knows a couple of new codes introduced in PostgreSQL 9.0.

  • Dropped deprecated Psycopg “own quoting”.

  • Never issue a ROLLBACK on close/GC. This behaviour was introduced as a bug in release 2.2, but trying to send a command while being destroyed has been considered not safe.

Bug fixes:

  • Fixed use of PQfreemem instead of free in binary typecaster.

  • Fixed access to freed memory in conn_get_isolation_level().

  • Fixed crash during Decimal adaptation with a few 2.5.x Python versions (ticket #7).

  • Fixed notices order (ticket #9).

What’s new in psycopg 2.2.2

Bux fixes:

  • the call to logging.basicConfig() in has been dropped: it was messing with some projects using logging (and a library should not initialize the logging system anyway.)

  • psycopg now correctly handles time zones with seconds in the UTC offset. The old register_tstz_w_secs() function is deprecated and will raise a warning if called.

  • Exceptions raised by the column iterator are propagated.

  • Exceptions raised by executemany() iterators are propagated.

What’s new in psycopg 2.2.1

Bux fixes:

  • psycopg now builds again on MS Windows.

What’s new in psycopg 2.2

This is the first release of the new 2.2 series, supporting not just one but two different ways of executing asynchronous queries, thanks to Jan and Daniele (with a little help from me and others, but they did 99% of the work so they deserve their names here in the news.)

psycopg now supports both classic select() loops and “green” coroutine libraries. It is all in the documentation, so just point your browser to doc/html/advanced.html.

Other new features:

  • truncate() method for lobjects.

  • COPY functions are now a little bit faster.

  • All builtin PostgreSQL to Python typecasters are now available from the psycopg2.extensions module.

  • Notifications from the backend are now available right after the execute() call (before client code needed to call isbusy() to ensure NOTIFY reception.)

  • Better timezone support.

  • Lots of documentation updates.

Bug fixes:

  • Fixed some gc/refcounting problems.

  • Fixed reference leak in NOTIFY reception.

  • Fixed problem with PostgreSQL not casting string literals to the correct types in some situations: psycopg now add an explicit cast to dates, times and bytea representations.

  • Fixed TimestampFromTicks() and TimeFromTicks() for seconds >= 59.5.

  • Fixed spurious exception raised when calling C typecasters from Python ones.

What’s new in psycopg 2.0.14

New features:

  • Support for adapting tuples to PostgreSQL arrays is now enabled by default and does not require importing psycopg2.extensions anymore.

  • “can’t adapt” error message now includes full type information.

  • Thank to Daniele Varrazzo (piro) psycopg2’s source package now includes full documentation in HTML and plain text format.

Bug fixes:

  • No loss of precision when using floats anymore.

  • decimal.Decimal “nan” and “infinity” correctly converted to PostgreSQL numeric NaN values (note that PostgreSQL numeric type does not support infinity but just NaNs.)

  • psycopg2.extensions now includes Binary.

It seems we’re good citizens of the free software ecosystem and that big big big companies and people ranting on the pgsql-hackers mailing list we’ll now not dislike us. g (See LICENSE file for the details.)

What’s new in psycopg 2.0.13

New features:

  • Support for UUID arrays.

  • It is now possible to build psycopg linking to a static libpq library.

Bug fixes:

  • Fixed a deadlock related to using the same connection with multiple cursors from different threads.

  • Builds again with MSVC.

What’s new in psycopg 2.0.12

New features:

  • The connection object now has a reset() method that can be used to reset the connection to its default state.

Bug fixes:

  • copy_to() and copy_from() now accept a much larger number of columns.

  • Fixed PostgreSQL version detection.

  • Fixed ZPsycopgDA version check.

  • Fixed regression in ZPsycopgDA that made it behave wrongly when receiving serialization errors: now the query is re-issued as it should be by propagating the correct exception to Zope.

  • Writing “large” large objects should now work.

What’s new in psycopg 2.0.11

New features:

  • DictRow and RealDictRow now use less memory. If you inherit on them remember to set __slots__ for your new attributes or be prepare to go back to old memory usage.

Bug fixes:

  • Fixed exception in

  • More robust detection of PostgreSQL development versions.

  • Fixed exception in RealDictCursor, introduced in 2.0.10.

What’s new in psycopg 2.0.10

New features:

  • A specialized type-caster that can parse time zones with seconds is now available. Note that after enabling it (see “wrong” time zones will be parsed without raising an exception but the result will be rounded.

  • DictCursor can be used as a named cursor.

  • DictRow now implements more dict methods.

  • The connection object now expose PostgreSQL server version as the .server_version attribute and the protocol version used as .protocol_version.

  • The connection object has a .get_parameter_status() methods that can be used to obtain useful information from the server.

Bug fixes:

  • None is now correctly always adapted to NULL.

  • Two double memory free errors provoked by multithreading and garbage collection are now fixed.

  • Fixed usage of internal Python code in the notice processor; this should fix segfaults when receiving a lot of notices in multithreaded programs.

  • Should build again on MSVC and Solaris.

  • Should build with development versions of PostgreSQL (ones with -devel version string.)

  • Fixed some tests that failed even when psycopg was right.

What’s new in psycopg 2.0.9

New features:

  • “import psycopg2.extras” to get some support for handling times and timestamps with seconds in the time zone offset.

  • DictCursors can now be used as named cursors.

Bug fixes:

  • register_type() now accept an explicit None as its second parameter.

  • psycopg2 should build again on MSVC and Solaris.

What’s new in psycopg 2.0.9

New features:

  • COPY TO/COPY FROM queries now can be of any size and psycopg will correctly quote separators.

  • float values Inf and NaN are now correctly handled and can round-trip to the database.

  • executemany() now return the numer of total INSERTed or UPDATEd rows. Note that, as it has always been, executemany() should not be used to execute multiple SELECT statements and while it will execute the statements without any problem, it will return the wrong value.

  • copy_from() and copy_to() can now use quoted separators.

  • “import psycopg2.extras” to get UUID support.

Bug fixes:

  • register_type() now works on connection and cursor subclasses.

  • fixed a memory leak when using lobjects.

What’s new in psycopg 2.0.8

New features:

  • The connection object now has a get_backend_pid() method that returns the current PostgreSQL connection backend process PID.

  • The PostgreSQL large object API has been exposed through the Cursor.lobject() method.

Bug fixes:

  • Some fixes to ZPsycopgDA have been merged from the Debian package.

  • A memory leak was fixed in Cursor.executemany().

  • A double free was fixed in pq_complete_error(), that caused crashes under some error conditions.

What’s new in psycopg 2.0.7

Improved error handling:

  • All instances of psycopg2.Error subclasses now have pgerror, pgcode and cursor attributes. They will be set to None if no value is available.

  • Exception classes are now chosen based on the SQLSTATE value from the result. (#184)

  • The commit() and rollback() methods now set the pgerror and pgcode attributes on exceptions. (#152)

  • errors from commit() and rollback() are no longer considered fatal. (#194)

  • If a disconnect is detected during execute(), an exception will be raised at that point rather than resulting in “ProgrammingError: no results to fetch” later on. (#186)

Better PostgreSQL compatibility:

  • If the server uses standard_conforming_strings, perform appropriate quoting.

  • BC dates are now handled if psycopg is compiled with mxDateTime support. If using datetime, an appropriate ValueError is raised. (#203)

Other bug fixes:

  • If multiple sub-interpreters are in use, do not share the Decimal type between them. (#192)

  • Buffer objects obtained from psycopg are now accepted by psycopg too, without segfaulting. (#209)

  • A few small changes were made to improve DB-API compatibility. All the dbapi20 tests now pass.


  • The PSYCOPG_DISPLAY_SIZE option is now off by default. This means that display size will always be set to “None” in cursor.description. Calculating the display size was expensive, and infrequently used so this should improve performance.

  • New QueryCanceledError and TransactionRollbackError exceptions have been added to the psycopg2.extensions module. They can be used to detect statement timeouts and deadlocks respectively.

  • Cursor objects now have a “closed” attribute. (#164)

  • If psycopg has been built with debug support, it is now necessary to set the PSYCOPG_DEBUG environment variable to turn on debug spew.

What’s new in psycopg 2.0.6

Better support for PostgreSQL, Python and win32:

  • full support for PostgreSQL 8.2, including NULLs in arrays

  • support for almost all existing PostgreSQL encodings

  • full list of PostgreSQL error codes available by importing the psycopg2.errorcodes module

  • full support for Python 2.5 and 64 bit architectures

  • better build support on win32 platform

Support for per-connection type-casters (used by ZPsycopgDA too, this fixes a long standing bug that made different connections use a random set of date/time type-casters instead of the configured one.)

Better management of times and dates both from Python and in Zope.

copy_to and copy_from now take an extra “columns” parameter.

Python tuples are now adapted to SQL sequences that can be used with the “IN” operator by default if the psycopg2.extensions module is imported (i.e., the SQL_IN adapter was moved from extras to extensions.)

Fixed some small buglets and build glitches:

  • removed double mutex destroy

  • removed all non-constant initializers

  • fixed PyObject_HEAD declarations to avoid memory corruption on 64 bit architectures

  • fixed several Python API calls to work on 64 bit architectures

  • applied compatibility macros from PEP 353

  • now using more than one argument format raise an error instead of a segfault

What’s new in psycopg

  • Now it really, really builds on MSVC and older gcc versions.

What’s new in psycopg 2.0.5

  • Fixed various buglets such as:

    • segfault when passing an empty string to Binary()

    • segfault on null queries

    • segfault and bad keyword naming in .executemany()

    • OperationalError in connection objects was always None

  • Various changes to ZPsycopgDA to make it more zope2.9-ish.

  • connect() now accept both integers and strings as port parameter

What’s new in psycopg 2.0.4

  • Fixed float conversion bug introduced in 2.0.3.

What’s new in psycopg 2.0.3

  • Fixed various buglets and a memory leak (see ChangeLog for details)

What’s new in psycopg 2.0.2

  • Fixed a bug in array typecasting that sometimes made psycopg forget about the last element in the array.

  • Fixed some minor buglets in string memory allocations.

  • Builds again with compilers different from gcc (#warning about PostgreSQL version is issued only if __GCC__ is defined.)

What’s new in psycopg 2.0.1

  • ZPsycopgDA now actually loads.

What’s new in psycopg 2.0

  • Fixed handle leak on win32.

  • If available the new “safe” encoding functions of libpq are used.

  • django and tinyerp people, please switch to psycopg 2 _without_ using a psycopg 1 compatibility layer (this release was anticipated so that you all stop grumbling about psycopg 2 is still in beta.. :)

What’s new in psycopg 2.0 beta 7

  • Ironed out last problems with times and date (should be quite solid now.)

  • Fixed problems with some arrays.

  • Slightly better ZPsycopgDA (no more double connection objects in the menu and other minor fixes.)

  • ProgrammingError exceptions now have three extra attributes: .cursor (it is possible to access the query that caused the exception using error.cursor.query), .pgerror and .pgcode (PostgreSQL original error text and code.)

  • The build system uses pg_config when available.

  • Documentation in the doc/ directory! (With many kudos to piro.)

What’s new in psycopg 2.0 beta 6

  • Support for named cursors.

  • Safer parsing of time intervals.

  • Better parsing of times and dates, no more locale problems.

  • Should now play well with py2exe and similar tools.

  • The “decimal” module is now used if available under Python 2.3.

What’s new in psycopg 2.0 beta 5

  • Fixed all known bugs.

  • The initial isolation level is now read from the server and .set_isolation_level() now takes values defined in psycopg2.extensions.

  • .callproc() implemented as a SELECT of the given procedure.

  • Better docstrings for a few functions/methods.

  • Some time-related functions like psycopg2.TimeFromTicks() now take the local timezone into account. Also a tzinfo object (as per datetime module specifications) can be passed to the psycopg2.Time and psycopg2.Datetime constructors.

  • All classes have been renamed to exist in the psycopg2._psycopg module, to fix problems with automatic documentation generators like epydoc.

  • NOTIFY is correctly trapped.

What’s new in psycopg 2.0 beta 4

  • psycopg module is now named psycopg2.

  • No more segfaults when a UNICODE query can’t be converted to the backend encoding.

  • No more segfaults on empty queries.

  • psycopg2.connect() now takes an integer for the port keyword parameter.

  • “python bdist_rpm” now works.

  • Fixed lots of small bugs, see ChangeLog for details.

What’s new in psycopg 2.0 beta 3

  • ZPsycopgDA now works (except table browsing.)

  • psycopg build again on Python 2.2.

What’s new in psycopg 2.0 beta 2

  • Fixed ZPsycopgDA version check (ZPsycopgDA can now be imported in Zope.)

  • psycopg.extras.DictRow works even after a new query on the generating cursor.

  • Better for win32 (should build with MSCV or mingw.)

  • Generic fixed and memory leaks plugs.

What’s new in psycopg 2.0 beta 1

  • Officially in beta (i.e., no new features will be added.)

  • Array support: list objects can be passed as bound variables and are correctly returned for array columns.

  • Added the psycopg.psycopg1 compatibility module (if you want instant psycopg 1 compatibility just “from psycopg import psycopg1 as psycopg”.)

  • Complete support for BYTEA columns and buffer objects.

  • Added error codes to error messages.

  • The AsIs adapter is now exported by default (also Decimal objects are adapted using the AsIs adapter (when str() is called on them they already format themselves using the right precision and scale.)

  • The connect() function now takes “connection_factory” instead of “factory” as keyword argument.

  • New code to build on win32 using mingw and better error messages on missing datetime headers,

  • Internal changes that allow much better user-defined type casters.

  • A lot of bugfixes (binary, datetime, 64 bit arches, GIL, .executemany())

What’s new in psycopg 1.99.13

  • Added missing .executemany() method.

  • Optimized type cast from PostgreSQL to Python (psycopg should be even faster than before.)

What’s new in psycopg 1.99.12

  • .rowcount should be ok and in sync with psycopg 1.

  • Implemented the new COPY FROM/COPY TO code when connection to the backend using libpq protocol 3 (this also removes all asprintf calls: build on win32 works again.) A protocol 3-enabled psycopg can connect to an old protocol 2 database and will detect it and use the right code.

  • getquoted() called for real by the mogrification code.

What’s new in psycopg 1.99.11

  • ‘cursor’ argument in .cursor() connection method renamed to ‘cursor_factory’.

  • changed ‘tuple_factory’ cursor attribute name to ‘row_factory’.

  • the .cursor attribute is gone and connections and cursors are properly gc-managed.

  • fixes to the async core.

What’s new in psycopg 1.99.10

  • The adapt() function now fully supports the adaptation protocol described in PEP 246. Note that the adapters registry now is indexed by (type, protocol) and not by type alone. Change your adapters accordingly.

  • More configuration options moved from to setup.cfg.

  • Fixed two memory leaks: one in cursor deallocation and one in row fetching (.fetchXXX() methods.)

What’s new in psycopg 1.99.9

  • Added simple pooling code (psycopg.pool module).

  • Added DECIMAL typecaster to convert postgresql DECIMAL and NUMERIC types (i.e, all types with an OID of NUMERICOID.) Note that the DECIMAL typecaster does not set scale and precision on the created objects but uses Python defaults.

  • ZPsycopgDA back in and working using the new pooling code.

  • Isn’t that enough? :)

What’s new in psycopg 1.99.8

  • added support for UNICODE queries.

  • added UNICODE typecaster; to activate it just do:


    Note that the UNICODE typecaster override the STRING one, so it is not activated by default.

  • cursors now really support the iterator protocol.

  • solved the rounding errors in time conversions.

  • now cursors support .fileno() and .isready() methods, to be used in select() calls.

  • .copy_from() and .copy_in() methods are back in (still using the old protocol, will be updated to use new one in next release.)

  • fixed memory corruption bug reported on win32 platform.

What’s new in psycopg 1.99.7

  • added support for tuple factories in cursor objects (removed factory argument in favor of a .tuple_factory attribute on the cursor object); see the new module psycopg.extras for a cursor (DictCursor) that return rows as objects that support indexing both by position and column name.

  • added support for tzinfo objects in datetime.timestamp objects: the PostgreSQL type “timestamp with time zone” is converted to datetime.timestamp with a FixedOffsetTimezone initialized as necessary.

What’s new in psycopg 1.99.6

  • sslmode parameter from 1.1.x

  • various datetime conversion improvements.

  • now psycopg should compile without mx or without native datetime (not both, obviously.)

  • included various win32/MSVC fixes (pthread.h changes, winsock2 library, include path in, etc.)

  • ported interval fixes from 1.1.14/1.1.15.

  • the last query executed by a cursor is now available in the .query attribute.

  • conversion of unicode strings to backend encoding now uses a table (that still need to be filled.)

  • cursors now have a .mogrify() method that return the query string instead of executing it.

  • connection objects now have a .dsn read-only attribute that holds the connection string.

  • moved psycopg C module to _psycopg and made psycopg a python module: this allows for a neat separation of DBAPI-2.0 functionality and psycopg extensions; the psycopg namespace will be also used to provide python-only extensions (like the pooling code, some ZPsycopgDA support functions and the like.)

What’s new in psycopg 1.99.3

  • added support for python 2.3 datetime types (both ways) and made datetime the default set of typecasters when available.

  • added example:

What’s new in psycopg 1.99.3

  • initial working support for unicode bound variables: UTF-8 and latin-1 backend encodings are natively supported (and the example even works!)

  • added .set_client_encoding() method on the connection object.

  • added examples:,,

What’s new in psycopg 1.99.2

  • better typecasting:

    • DateTimeDelta used for postgresql TIME (merge from 1.1)

    • BYTEA now is converted to a real buffer object, not to a string

  • buffer objects are now adapted into Binary objects automatically.

  • ported scroll method from 1.1 (DBAPI-2.0 extension for cursors)

  • initial support for some DBAPI-2.0 extensions:

    • .rownumber attribute for cursors

    • .connection attribute for cursors

    • .next() and .__iter__() methods to have cursors support the iterator protocol

    • all exception objects are exported to the connection object

What’s new in psycopg 1.99.1

  • implemented microprotocols to adapt arbitrary types to the interface used by psycopg to bind variables in execute;

  • moved qstring, pboolean and mxdatetime to the new adapter layout (binary is still missing; python 2.3 datetime needs to be written).

What’s new in psycopg 1.99.0

  • reorganized the whole source tree;

  • async core is in place;

  • splitted QuotedString objects from mx stuff;

  • dropped autotools and moved to pythonic (needs work.)