System command wrappers

pykx.system

System command wrappers for PyKX.

SystemCommands

SystemCommands(q)

Wrappers for q system commands.

More documentation on all the system commands available to q can be found here.

tables

tables(namespace=None)

Lists the tables associated with a namespace/dictionary

Examples:

Retrieve the tables within a provided namespace:

kx.system.tables('.foo')

Retrieve the tables within a provided dictionary:

kx.system.tables('foo')

console_size writable property

console_size()

The maximum console size for the q process in the format rows, columns.

The size of the output for the q process before truncating the rest with ....

Expects a 2 item list denoting the console width and console height.

Note: Does not work over IPC, only within EmbeddedQ.

Examples:

Get the maximum console_size size of output for EmbeddedQ to 10 columns and 10 rows.

kx.q.system.console_size

Set the maximum console size of output for EmbeddedQ to 10 columns and 10 rows.

kx.q.system.console_size = [10, 10]

display_size writable property

display_size()

The maximum console display size for the q process in the format rows, columns.

The size of the output for the q process before truncating the rest with ....

Expects a 2 item list denoting the display width and console height.

Note: Does not work over IPC, only within EmbeddedQ.

Examples:

Get the maximum display size of output for EmbeddedQ to 10 columns and 10 rows.

kx.q.system.display_size

Set the maximum display size of output for EmbeddedQ to 10 columns and 10 rows.

kx.q.system.display_size = [10, 10]

cd

cd(directory=None)

Get the current directory or change the current directory.

Examples:

Get the current working directory.

kx.q.system.cd()

Change the current working directory to the root directory on a UNIX like machine.

kx.q.system.cd('/')

namespace

namespace(ns=None)

Get the current namespace or change to a new namespace.

Examples:

Get the current namespace.

kx.q.system.namespace()

Change the current namespace to .foo, note the leading . may be ommited.

kx.q.system.namespace('foo')

Return to the default namespace.

kx.q.system.namespace('')

functions

functions(ns=None)

Get the functions available in the current namespace or functions in a provided namespace or dictionary.

Examples:

Get the functions within the current namespace.

kx.q.system.functions()

Get the functions within the .foo namespace.

kx.q.system.functions('.foo')

Get the functions within a dictionary.

kx.q.system.function('foo')

garbage_collection writable property

garbage_collection()

The current garbage collection mode that q will use.

0 - default deferred collection. 1 - immediate collection.

Examples:

Get the current garbage collection mode.

kx.q.system.garbage_collection

Set the current garbage collection mode to immediate collection.

kx.q.system.garbage_collection = 1

load

load(path)

Loads a q script or a directory of a splayed table.

Examples:

Load a q script named foo.q.

kx.q.system.load('foo.q')

utc_offset writable property

utc_offset()

Get the local time offset as an integer from UTC.

If abs(offset) > 23 then return the offset in minutes.

Examples:

Get the current local time offset.

kx.q.system.utc_offset

Set the current local time offset to be -4:00 from UTC.

kx.q.system.utc_offset = -4

precision writable property

precision()

Get the precision for floating point numbers (number of digits shown).

Note: Setting this property does not work over IPC, only works within EmbeddedQ.

Examples:

Get the current level of float precision.

kx.q.system.precision

Set the Level of float precision to 2.

kx.q.system.precision = 2

rename

rename(src, dest)

Rename file src to dest.

Equivalent to the unix mv command or Windows move command.

Note: Cannot rename to a different disk.

Examples:

Rename a file foo.q to bar.q.

kx.q.system.rename('foo.q', 'bar.q')

max_num_threads writable property

max_num_threads()

The maximum number of secondary threads available to q.

This value can be set using the -s command-line flag, provided to q via the $QARGS environment variable. For example: QARGS='-s 8' python, or QARGS='-s 0' python.

num_threads writable property

num_threads()

The current number of secondary threads being used by q.

Computations in q will automatically be parallelized across this number of threads as q deems appropriate.

This property is meant to be modified on EmbeddedQ and QConnection instances.

Examples:

Set the number of threads for embedded q to use to 8.

kx.q.num_threads = 8

Set the number of threads for a q process being connected to over IPC to 8.

q = kx.SyncQConnection('localhost', 5001)
q.num_threads = 8

random_seed writable property

random_seed()

The last value the the random seed was initialized with.

Examples:

Get the current seed value.

kx.q.system.random_seed

Set the random seed value to 23.

kx.q.system.random_seed = 23

variables

variables(ns=None)

Get the variables in the current namespace or variables in a given namespace.

Examples:

Get the variables defined in the current namespace.

kx.q.system.variables()

Get the variables associated with a q namespace/dictionary

kx.q.system.variables('.foo')
kx.q.system.variables('foo')

workspace property

workspace()

Outputs various information about the current memory usage of the q process.

Examples:

Get the memory usage of EmbeddedQ.

kx.q.system.workspace

week_offset writable property

week_offset()

The start of week offset where 0 is Saturday.

Examples:

Get the current week offset.

kx.q.system.week_offset

Set the current week offset so Monday is the first day of the week.

kx.q.system.week_offset = 2

date_parsing writable property

date_parsing()

Get the current format for date parsing.

0 - is for mm/dd/yyyy 1 - is for dd/mm/yyyy

Examples:

Get the current value for date parsing.

kx.q.system.date_parsing

Get the current value for date parsing so the format is dd/mm/yyyy.

kx.q.system.date_parsing = 1