Loading KDB-X Modules

This page documents how to load KDB-X q modules into Python with kx.use, the QModule objects returned, and the SearchPath used to locate them.

pykx.module

Loading KDB-X modules.

When pykx.use is called KDB-X will attempt to load a module with the given name.

QModule

QModule(name, qns, qkeys, qdict)

A loaded KDB-X q Module.

Example loading the pq module and the pq.t submodule within KDB-X Python.

>>> import pykx as kx
>>> pq = kx.use('kx.pq')
>>> pq
pykx.QModule(pykx.q('
pq| pykx.Lambda
op| pykx.Lambda
rd| pykx.Lambda
'))
>>> pq.t = kx.use('kx.pq.t')
>>> pq
pykx.QModule(pykx.q('
pq| pykx.Lambda
op| pykx.Lambda
rd| pykx.Lambda
t | pykx.QModule(pykx.q('
    mkT| pykx.Lambda
    mkP| pykx.Lambda
    tt | pykx.Lambda
    mt | pykx.Lambda
    fv | pykx.Lambda
    '))
'))

use

use(module_name, export_argument=None)

Function for loading KDB-X modules.

Parameters:

Name	Type	Description	Default
module_name	str	The name of the KDB-X module to load as a string.	required
export_argument	object	Optional argument to pass to the module export function. Default None.	None

Returns:

Type	Description
QModule	A loaded QModule instance.

Examples:

Example loading the pq module and the pq.t submodule within KDB-X Python.

>>> import pykx as kx
>>> from pathlib import Path
>>> pq = kx.module.use('kx.pq')
>>> pq.t = kx.module.use('kx.pq.t')
>>> tab = pq.pq(Path('../types.parquet'))
>>> tab
pykx.VirtualTable(pykx.q('`T!`f`m`t!(k){[f;t;c;b;a;v]g:$[s:-1h=@b;0;#b];(bf;b1):$[g;df[t;0,0b;b];(::;()..'))
>>> tab.select()
pykx.Table(pykx.q('
col0 col1 col2
---------------
1    1    "asd"
1    2    "bsd"
0    3    "csd"
1    4    "asd"
0    5    "bsd"
0    6    "csd"
1    7    "asd"
0    8    "bsd"
0    9    "csd"
'))

SearchPath

SearchPath(
    entry=None, *, add=False, remove=False, prepend=False, strict=False, allow_duplicates=False
)

Manage the module SearchPath.

Parameters:

Name	Type	Description	Default
entry	Optional[str]	The path string to add or remove. If omitted, the current SearchPath is returned.	None
add	bool	If True, add the entry to the SearchPath. Default False.	False
remove	bool	If True, remove all occurrences of the entry from the SearchPath. Default False.	False
prepend	bool	If True, insert the entry at the front rather than the end. Default False.	False
strict	bool	If True, raise a ValueError when attempting to remove an entry that is not present. Default False.	False
allow_duplicates	bool	If True, allow the same entry to appear more than once in the SearchPath. Default False.	False

Examples:

Retrieve the current SearchPath:

>>> kx.module.SearchPath()
[]

Append and prepend entries:

>>> kx.module.SearchPath("/home/user/.kx/mod", add=True)
>>> kx.module.SearchPath("/home/user/mod", add=True)
>>> kx.module.SearchPath("/other/mod", add=True, prepend=True)
>>> kx.module.SearchPath()
['/other/mod', '/home/user/.kx/mod', '/home/user/mod']

Remove an entry:

>>> kx.module.SearchPath("/other/mod", remove=True)
>>> kx.module.SearchPath()
['/home/user/.kx/mod', '/home/user/mod']