Jupyter q Magic Command

In [2]:

import pykx as kx

import pykx as kx

Create the external q process¶

To run this example, the Python code in the following cell will do the equivalent to executing the following in a terminal:

$ q -p 5001

In [3]:

import subprocess
import time
proc = subprocess.Popen(
    ('q', '-p', '5001')
)
time.sleep(5)

import subprocess import time proc = subprocess.Popen( ('q', '-p', '5001') ) time.sleep(5)

Executing against Embedded q¶

A cell beginning with %%q will execute q within PyKX's EmbeddedQ module.

In [4]:

%%q
til 10

%%q til 10

0 1 2 3 4 5 6 7 8 9

Execution options¶

Execution options can also be included after %%q.

Here is the list of currently supported execution options.

--debug: prints the q backtrace before raising a QError
      if the cell errors
--display: calls display rather than the default print
      on returned objects

In [5]:

%%q
([] a: 1 2 3)

%%q ([] a: 1 2 3)

a
-
1
2
3

In [6]:

%%q --display
([] a: 1 2 3)

%%q --display ([] a: 1 2 3)

	a
0	1
1	2
2	3

Executing against an external q process over IPC¶

Connection information can also be included after the %%q to connect to a remote q process over IPC.

Here is the list of currently supported connection parameters. If they specify a type a second value is expected to follow them to be used as the parameter. If no type follows them they can be used as a stand alone flag.

--host: A string object denoting the host to connect to
--port: An int object denoting the port to connect over
--user: A str object denoting the username to use when connecting
--password: A str object denoting the password to use when connecting
--timeout: A float object denoting the time in seconds before the query
      times out, defaults to no timeout
--nolarge: Disable messages over 2GB being sent / received
--tls: Use a tls connection
--unix: Use a unix connection
--reconnection_attempts: An int object denoting how many
      reconnection attempts to make
--noctx: Disable the context interface

Connect to a q server running on localhost at port 5001 as user using password password and disable the context interface.

In [7]:

%%q --host localhost --port 5001 --user user --pass password --noctx
til 10

%%q --host localhost --port 5001 --user user --pass password --noctx til 10

0 1 2 3 4 5 6 7 8 9

All connection arguments are optional with the exception of the --port argument. If --host is not provided localhost will be used as the default host.

In [8]:

%%q --port 5001
tab:([]a:1000?1000; b:1000?500.0; c:1000?`AAPL`MSFT`GOOG);

%%q --port 5001 tab:([]a:1000?1000; b:1000?500.0; c:1000?`AAPL`MSFT`GOOG);

It is possible to execute q code spanning multiple lines.

In [9]:

%%q --port 5001
afunc: {[x; y]
  x + y  
  };
afunc[0; 1]
afunc[2; 3]

%%q --port 5001 afunc: {[x; y] x + y }; afunc[0; 1] afunc[2; 3]

1
5

Using the SQL interface¶

The s) syntax to run SQL queries against local tables within the q process.

Note: The s.k_ library must be loaded first to use the SQL interface

In [10]:

%%q --port 5001
\l s.k_
s) select * from tab where a>500 and b<250.0 limit 5

%%q --port 5001 \l s.k_ s) select * from tab where a>500 and b<250.0 limit 5

a   b        c   
-----------------
916 149.4238 AAPL
898 97.74763 MSFT
900 45.35602 MSFT
677 150.6862 MSFT
741 151.1293 MSFT

Using namespaces¶

You can also use q namespaces, and switch between them using \d.

Note: The namespace is reset back to the base namespace . between cells.

In [11]:

%%q --port 5001
\d .example
f: {[x] til x};

%%q --port 5001 \d .example f: {[x] til x};

In [12]:

%%q --port 5001
\d
.example.f[10]

%%q --port 5001 \d .example.f[10]

.
0 1 2 3 4 5 6 7 8 9

In [13]:

# Shutdown the q process we were connected to for the IPC demo
proc.kill()

# Shutdown the q process we were connected to for the IPC demo proc.kill()