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Changelog

PyKX 1.4.2

Fixes and Improvements

  • Fixed an issue causing EmbeddedQ to fail to load.

PyKX 1.4.1

Additions

  • Added constructors for Table and KeyedTable objects to allow creation of these objects from dictionaries and list like objects.

Fixes and Improvements

  • Fixed a memory leak around calling wrapped Foreign objects in pykx.q.
  • Fixed an issue around the tls keyword argument when creating QConnection instances, as well as a bug in the unlicensed behaviour of SecureQConnection's.

PyKX 1.4.0

Additions

  • Addition of a utility function kx.ssl_info() to retrieve the SSL configuration when running in unlicensed mode (returns the same info as kx.q('-26!0') with a license).
  • Addition of a utility function kx.schema.builder to allow for the generation of pykx.Table and pykx.KeyedTable types with a defined schema and zero rows, this provides an alternative to writing q code to create an empty table.
  • Added helper functions for inserting and upserting to k.Table instances. These functions provide new keyword arguments to run a test insert against the table or to enforce that the schema of the new row matches the existing table.
  • Added environment variable PYKX_NOQCE=1 to skip the loading of q Cloud Edition in order to speed up the import of PyKX.
  • Added environment variable PYKX_LOAD_PYARROW_UNSAFE=1 to import PyAarrow without the "subprocess safety net" which is here to prevent some hard crashes (but is slower than a simple import).
  • Addition of method file_execute to kx.QConnection objects which allows the execution of a local .q script on a server instance as outlined here.
  • Added kx.RawQConnection which extends kx.AsyncQConnection with extra functions that allow a user to directly poll the send and receive selectors.
  • Added environment variable PYKX_RELEASE_GIL=1 to drop the Python GIL on calls into embedded q.
  • Added environment variable PYKX_Q_LOCK=1 to enable a Mutex Lock around calls into q, setting this environment variable to a number greater than 0 will set the max length in time to block before raising an error, a value of '-1' will block indefinitely and will not error, any other value will cause an error to be raised immediately if the lock cannot be acquired.
  • Added insert and upsert methods to Table and KeyedTable objects.

Fixes and Improvements

  • Fixed has_nulls and has_infs properties for subclasses of k.Collection.
  • Improved error output of kx.QConnection objects when an error is raised within the context interface.
  • Fixed .py() conversion of nested k.Dictionary objects and keyed k.Dictionary objects.
  • Fixed unclear error message when querying a QConnection instance that has been closed.
  • Added support for conversions of non C contiguous numpy arrays.
  • Fixed conversion of null GUIDAtom's to and from numpy types.
  • Improved performance of converting q enums to pandas Categoricals.

Beta Features

  • Added support for a Pandas like API around Table and KeyedTable instances, documentation for the specific functionality can be found here.
  • Added .pykx.setdefault to pykx.q which allows the default conversion type to be set without using environment variables.

PyKX 1.3.2

Features and Fixes

  • Fixed support for using TLS with SyncQConnection instances.

PyKX 1.3.1

Features and Fixes

  • Added environment variable PYKX_Q_LIB_LOCATION to specify a path to load the PyKX q libraries from.
    • Required files in this directory
      • If you are using the kdb+/q Insights core libraries they all must be present within this folder.
      • The read.q, write.q, and csvutil.q libraries that are bundled with PyKX.
      • A q.k that matches the version of q you are loading.
      • There must also be a subfolder (l64 / m64 / w64) based on the platform you are using.
        • Within this subfolder a copy of these files must also be present.
          • libq.(so / dylib) / q.dll.
          • libe.(so / dylib) / e.dll.
          • If using the Insights core libraries their respective shared objects must also be present here.
  • Updated core q libraries
    • PyKX now supports M1 Macs
    • OpenSSLv3 support
  • Added ability to specify maximum length for IPC error messages. The default is 256 characters and this can be changed by setting the PYKX_MAX_ERROR_LENGTH environment variable.

PyKX 1.3.0

Features and Fixes

  • Support for converting datetime.datetime objects with timezone information into pykx.TimestampAtoms and pykx.TimestampVectors.
  • Added a magic command to run cells of q code in a Jupyter Notebook. The addition of %%q at the start of a Jupyter Notebook cell will allow a user to execute q code locally similarly to loading a q file.
  • Added no_ctx key word argument to pykx.QConnection instances to disable sending extra queries to/from q to manage the context interface.
  • Improvements to SQL interface for PyKX including the addition of support for prepared statements, execution of these statements and retrieval of inputs see here for more information.
  • Fix to memory leak seen when converting Pandas Dataframes to q tables.
  • Removed unnecessary copy when sending q objects over IPC.

Beta Features

  • EmbedPy replacement functionality pykx.q updated significantly to provide parity with embedPy from a syntax perspective. Documentation of the interface here provides API usage. Note that initialisation requires the first version of Python to be retrieved on a users PATH to have PyKX installed. Additional flexibility with respect to installation location is expected in 1.4.0 please provide any feedback to pykx@kx.com

PyKX 1.2.2

Features and Fixes

  • Fixed an issue causing the timeout argument for QConnection instances to not work work properly.

PyKX 1.2.1

Features and Fixes

  • Added support for OpenSSLv3 for IPC connections created when in 'licensed' mode.
  • Updated conversion functionality for timestamps to support conversions within Pandas 1.5.0

PyKX 1.2.0

Features and Fixes

  • Support for converting any python type to a q Foreign object has been added.
  • Support for converting Pandas categorical types into pykx.EnumVector type objects.
  • Support for q querying against Pandas/PyArrow tables through internal conversion to q representation and subsequent query. kx.q.qsql.select(<pd.DataFrame>)
  • Support for casting Python objects prior to converting into K objects. (e.g. kx.IntAtom(3.14, cast=True) or kx.toq("3.14", ktype=kx.FloatAtom, cast=True)).
  • Support usage of numpy __array_ufunc__'s directly on pykx.Vector types.
  • Support usage of numpy __array_function__'s directly on pykx.Vector types (Note: these will return a numpy ndarray object not an analogous pykx.K object).
  • Improved performance of pykx.SymbolVector conversion into native Python type (e.g. .py() conversion for pykx.SymbolVector's).
  • Improved performance and memory usage of various comparison operators between K types.
  • Improved performance of various pykx.toq conversions.
  • pykx.Vector types will now automatically enlist atomic types instead of erroring.
  • Fixed conversions of numpy float types into pykx.FloatAtom and pykx.RealAtom types.
  • Fixed conversion of None Python objects into analogous null K types if a ktype is specified.
  • Added event_loop parameter to pykx.AsyncQConnection that takes a running event loop as a parameter and allows the event loop to manage pykx.QFuture objects.

Beta Features

  • Added extra functionality to pykx.q related to the calling and use of python foreign objects directly within a q process.
  • Support for NEP-49, which allows numpy arrays to be converted into q Vectors without copying the underlying data. This behaviour is opt-in and you can do so by setting the environment variable PYKX_ALLOCATOR to 1, "1" or True or by adding the flag --pykxalloc to the QARGS environment variable. Note: This feature also requires a python version of at least 3.8.
  • Support the ability to trigger early garbage collection of objects in the q memory space by adding --pykxgc to the QARGS environment variable, or by setting the PYKX_GC environment variable to 1, "1" or True.

PyKX 1.1.1

Features & Fixes

  • Added ability to skip symlinking $QHOME to PyKX's local $QHOME by setting the environment variable IGNORE_QHOME.

PyKX 1.1.0

Dependencies

  • The dependency on the system library libcurl has been made optional for Linux. If it is missing on Linux, a warning will be emitted instead of an error being raised, and the KX Insights Core library kurl will not be fully loaded. Windows and macOS are unaffected, as they don't support the KX Insights Core features to begin with.

Features & Fixes

  • Splayed and partitioned tables no longer emit warnings when instantiated.
  • Added pykx.Q.sql, which is a wrapper around KXI Core SQL.
  • .pykx.pyexec and .pykx.pyeval no longer segfault when called with a character atom.
  • Updated several pykx.toq tests so that they would not randomly fail.
  • Fixed error when pickling pykx.util.BlockManager in certain esoteric situations.
  • Fixed pandas.MultiIndex objects created by PyKX having pykx.SymbolAtom objects within them - now they have str objects instead, as they normally would.
  • Upgraded the included KX Insights Core libraries to version 3.0.0.
  • Added pykx.toq.from_datetime_date, which converts datetime.date objects into any q temporal atom that can represent a date (defaulting to a date atom).
  • Fixed error when user specifies -s or -q in $QARGS.
  • Fixed recursion error when accessing a non-existent attribute of pykx.q while in unlicensed mode. Now an attribute error is raised instead.
  • Fixed build error introduced by new rules enforced by new versions of setuptools.
  • Added pykx.Anymap.
  • Fixed support for kx.lic licenses.
  • The KXIC libraries are now loaded after q has been fully initialized, rather than during the initialization. This significantly reduces the time it takes to import PyKX.
  • PyKX now uses a single location for $QHOME: its lib directory within the installed package. The top-level contents of the $QHOME directory (prior to PyKX updating the env var when embedded q is initialized) will be symlinked into PyKX's lib directory, along with the content of any subdirectories under lib (e.g. l64, m64, w64). This enables loading scripts and libraries located in the original $QHOME directory during q initialization.
  • Improved performance (both execution speed and memory usage) of calling np.array on pykx.Vector instances. The best practice is still to use the np method instead of calling np.array on the pykx.Vector instance.
  • pykx.Vector is now a subclass of collections.abc.Sequence.
  • pykx.Mapping is not a subclass of collections.abc.Mapping.
  • Split pykx.QConnection into pykx.SyncQConnection and pykx.AsyncQConnection and added support for asynchronous IPC with q using async/await. Refer to the pykx.AsyncQConnection docs for more details.
  • Pandas dataframes containing Pandas extension arrays not originally created as Numpy arrays would result in errors when attempting to convert to q. For example a Dataframe with index of type pandas.MultiIndex.from_arrays would result in an error in conversion.
  • Improved performance of converting pykx.SymbolVector to numpy.array of strings, and also the conversion back from a numpy.array of strings to a q SymbolVector.
  • Improved performance of converting numpy.array's of dtypes datetime64/timedelta64 to the various pykx.TemporalTypes.

PyKX 1.0.1

Deprecations & Removals

  • The sync parameter for pykx.QConnection and pykx.QConnection.__call__ has been renamed to the less confusing name wait. The sync parameter remains, but its usage will result in a DeprecationWarning being emitted. The sync parameter will be removed in a future version.

Features & Fixes

  • Updated to stable classifier (Development Status :: 5 - Production/Stable) in project metadata. Despite this update being done in version 1.0.1, version 1.0.0 is still the first stable release of PyKX.
  • PyKX now provides source distributions (sdist). It can be downloaded from PyPI using pip download --no-binary=:all: --no-deps pykx. As noted in the installation docs, installations built from the source will only receive support on a best-effort basis.
  • Fixed Pandas NaT conversion to q types. Now pykx.toq(pandas.NaT, ktype=ktype) produces a null temporal atom for any given ktype (e.g. pykx.TimeAtom).
  • Added a doc page for limitations of embedded q.
  • Added a test to ensure large vectors are correctly handled (5 GiB).
  • Always use synchronous queries internally, i.e. fix QConnection(sync=False).
  • Disabled the context interface over IPC. This is a temporary measure that will be reversed once q function objects are updated to run in the environment they were defined in by default.
  • Reduced the time it takes to import PyKX. There are plans to reduce it further, as import pykx remains fairly slow.
  • Updated to KXI Core 2.1 & rename qce -> kxic.
  • Misc test updates.
  • Misc doc updates.

PyKX 1.0.0

Migration Notes

To switch from Pykdb to PyKX, you will need to update the name of the dependency from pykdb to pykx in your pyproject.toml/requirements.txt/setup.cfg/etc. When Pykdb was renamed to PyKX, its version number was reset. The first public release of PyKX has the version number 1.0.0, and will employ semantic versioning.

Pay close attention to the renames listed below, as well as the removals. Many things have been moved to the top-level, or otherwise reorganized. A common idiom with Pykdb was the following:

from pykdb import q, k

It is recommended that the following be used instead:

import pykx as kx

This way the many attributes at the top-level can be easily accessed without any loss of context, for example:

kx.q # Can be called to execute q code
kx.K # Base type for objects in q; can be used to convert a Python object into a q type
kx.SymbolAtom # Type for symbol atoms; can be used to convert a `str` or `bytes` into a symbol atom
kx.QContext # Represents a q context via the PyKX context interface
kx.QConnection # Can be called to connect to a q process via q IPC
kx.PyKXException # Base exception type for exceptions specific to PyKX and q
kx.QError # Exception type for errors that occur in q
kx.LicenseException # Exception type raised when features that require a license are used without
kx.QHOME # Path from which to load q files, set by $QHOME environment variable
kx.QARGS # List of arguments provided to the embedded q instance at startup, set by $QARGS environment variable
# etc.

You can no longer rely on the context being reset to the global context after each call into embedded q, however IPC calls are unaffected.

Renames

  • Pykdb has been renamed to PyKX. Pykdb -> PyKX; PYKDB -> PYKX; pykdb -> pykx.
  • The adapt module has been renamed to toq, and it can be called directly. Instead of pykdb.adapt.adapt(x) one should write pykx.toq(x).
  • The k module has been renamed to wrappers. All wrapper classes can be accessed from the top-level, i.e. pykx.K, pykx.SymbolAtom, etc.
  • The "module interface" (pykdb.module_interface) has been renamed to the "context interface" (pykx.ctx). All pykx.Q instances (i.e. pykx.q and all pykx.QConnection instances) have a ctx attribute, which is the global QContext for that pykx.Q instance. Usually, one need not directly access the global context. Instead, one can access its subcontexts directly e.g. q.dbmaint instead of q.ctx.dbmaint.
  • KdbError (and its subclasses) have been renamed to QError
  • pykdb.ctx.KdbContext has been renamed to pykx.ctx.QContext, and is available from the top-level, i.e. pykx.QContext.
  • The Connection class in the IPC module has been renamed to QConnection, and is now available at the top-level, i.e. pykx.QConnection.
  • The q type wrapper DynamicLoad has been renamed to Foreign (pykdb.k.DynamicLoad -> pykx.Foreign).

Deprecations & Removals

  • The pykdb.q.ipc attribute has been removed. The IPC module can be accessed directly instead at pykx.ipc, but generally one will only need to access the QConnection class, which can be accessed at the top-level: pykx.QConnection.
  • The pykdb.q.K attribute has been removed. Instead, K types can be used as constructors for that type by leveraging the toq module. For example, instead of pykdb.q.K(x) one should write pykx.K(x). Instead of pykx.q.K(x, k_type=pykx.k.SymbolAtom) one should write pykx.SymbolAtom(x) or pykx.toq(x, ktype=pykx.SymbolAtom).
  • Most KdbError/QError subclasses have been removed, as identifying them is error prone, and we are unable to provide helpful error messages for most of them.
  • The pykx.kdb singleton class has been removed.

Dependencies

  • More Numpy, Pandas, and PyArrow versions are supported. Current pandas~=1.0, numpy~=1.20,<1.22, and pyarrow>=3.0.0 are supported. PyArrow remains an optional dependency.
  • A dependency on find-libpython~=0.2 was added. This is only used when running PyKX under a q process (see details in the section below about new alpha features).
  • A dependency on the system library libcurl was added for Linux. This dependency will be made optional in a future release.

Features & Fixes

  • The pykx.Q class has been added as the base class for pykx.EmbeddedQ (the class for pykx.q) and pykx.QConnection.
  • The pykx.EmbeddedQ process now perisists its context between calls.
  • The console now works over IPC.
  • The query module now works over IPC. Because K objects hold no reference to the q instance that created them (be it local or over IPC), K tables no longer have select/exec/update/delete methods with themselves projected in as the first argument. That is to say, instead of writing t.select(...), write q.qsql.select(t, ...), where q is either pykx.q or an instance of pykx.QConnection, and t was obtained from q.
  • The context interface now works over IPC.
  • Nulls and infinities are now handled as nulls and infinities, rather than as their underlying values. pykx.Atom.is_null, pykx.Atom.is_inf, pykx.Collection.has_nulls, and pykx.Collection.has_infs have been added. Numpy, Pandas, and PyArrow handles integral nulls with masked arrays, and they handle temporal nulls with NaT. NaN continues to be used for real/float nulls. The general Python representation (from .py()) uses K objects for nulls and infinities.
  • Calling bool on pykx.K objects now either raises a TypeError, or return the unambiguously correct result. For ambiguous cases such as pykx.Collection instances, use .any(), .all(), or a length check instead.
  • Assignment to q reserved words or the q context now raises a pykx.PyKXException.
  • pykx.toq.from_list (previously pykdb.adapt.adapt_list) now works in unlicensed mode.
  • q.query and q.sql are now placeholders (set to None). The query interface can be accessed from q.qsql.
  • Ternary pow now raises TypeError for RealNumericVector and RealNumericAtom.
  • QContext objects are now context handlers, e.g. with pykx.q.dbmaint: # operate in .dbmaint within this block. This context handler supports arbitrary nesting.
  • __getitem__ now raises a pykx.LicenseException when used in unlicensed mode. Previously it worked for a few select types only. If running in unlicensed mode, one should perform all q indexing in the connected q process, and all Python indexing after converting the K object to a Python/Numpy/Pandas/PyArrow object.
  • pykx.QConnection (previously pykdb.ipc.Connection) objects now have an informative/idiomatic repr.
  • Calls to pykx.q now support up to 8 arguments beyond the required query at position 0, similar to calling pykx.QConnection instances. These arguments are applied to the result of the query.
  • Embedded q is now used to count the number of rows a table has.
  • All dynamic linking to libq and libe has been replaced by dynamic loading. As a result, the modules previously known as adapt and adapt_unlicensed have been unified under pykx.toq.
  • PyKX now attempts to initialize embedded q when pykx is imported, rather than when pykx.q is first accessed. As a result, the error-prone practice of supplying the pykx.kdb singleton class with arguments for embedded q is now impossible.
  • Arguments for embedded q can now be supplied via the environment variable $QARGS in the form of command-line arguments. For example, QARGS='--unlicensed' causes PyKX to enter unlicensed mode when it is started, and QARGS='-o 8' causes embedded q to use an offset from UTC of 8 hours. These could be combined as QARGS='--unlicensed -o 8'.
  • Added the --licensed startup flag (to be provided via the $QARGS environment variable), which can be used to raise a pykx.PyKXException (rather than emitting a warning) if PyKX fails to start in licensed mode (likely because of a missing/invalid q license).
  • PyKX Linux wheels are now PEP 600 compliant, built to the manylinux_2_17 standard.
  • Misc other bug fixes.
  • Misc doc improvements.

Performance Improvements

  • Converting nested lists from q to Python is much faster.
  • Internally, PyKX now calls q functions with arguments directly instead of creating a pykx.Function instance then calling it. This results in modest performance benefits in some cases.
  • The context interface no longer loads every element of a context when the context is first accessed, thereby removing the computation spike, which could be particularly intense for large q contexts.

New Alpha Features

Alpha features are subject to change

Alpha features are not stable will be subject to changes without notice. Use at your own risk.

  • q can now load PyKX by loading the q file pykx.q. pykx.q can be copied into $QHOME by running pykx.install_into_QHOME(). When loaded into q, it will define the .pykx namespace, which notably has .pykx.exec and .pykx.pyeval. This allows for Python code to be run within q libraries and applications without some of the limitations of embedded q such as the lack of the q main loop, or the lack of timers. When q loads pykx.q, it attempts to source the currently active Python environment by running python, then fetching the environment details from it.