OpenSearch/docs/plugins/lang-python.asciidoc

187 lines
3.6 KiB
Plaintext

[[lang-python]]
=== Python Language Plugin
deprecated[5.0.0,Python will be replaced by the new scripting language {ref}/modules-scripting-painless.html[`Painless`]]
The Python language plugin enables the use of Python in Elasticsearch
scripts, via the http://www.jython.org/[Jython] Java implementation of Python.
[[lang-python-install]]
[float]
==== Installation
This plugin can be installed using the plugin manager:
[source,sh]
----------------------------------------------------------------
sudo bin/elasticsearch-plugin install lang-python
----------------------------------------------------------------
The plugin must be installed on every node in the cluster, and each node must
be restarted after installation.
[[lang-python-remove]]
[float]
==== Removal
The plugin can be removed with the following command:
[source,sh]
----------------------------------------------------------------
sudo bin/elasticsearch-plugin remove lang-python
----------------------------------------------------------------
The node must be stopped before removing the plugin.
[[lang-python-usage]]
==== Using Python in Elasticsearch
Once the plugin has been installed, Python can be used at a scripting
language by setting the `lang` parameter to `python`.
Scripting is available in many APIs, but we will use an example with the
`function_score` for demonstration purposes:
[[lang-python-inline]]
[float]
=== Inline scripts
WARNING: Enabling inline scripting on an unprotected Elasticsearch cluster is dangerous.
See <<lang-python-file>> for a safer option.
If you have enabled {ref}/modules-scripting-security.html#enable-dynamic-scripting[inline scripts],
you can use Python as follows:
[source,js]
----
PUT test/doc/1
{
"num": 1.0
}
PUT test/doc/2
{
"num": 2.0
}
GET test/_search
{
"query": {
"function_score": {
"script_score": {
"script": {
"inline": "doc[\"num\"].value * factor",
"lang": "python",
"params": {
"factor": 2
}
}
}
}
}
}
----
// CONSOLE
[[lang-python-stored]]
[float]
=== Stored scripts
WARNING: Enabling stored scripts on an unprotected Elasticsearch cluster is dangerous.
See <<lang-python-file>> for a safer option.
If you have enabled {ref}/modules-scripting-security.html#enable-dynamic-scripting[stored scripts],
you can use Python as follows:
[source,js]
----
PUT test/doc/1
{
"num": 1.0
}
PUT test/doc/2
{
"num": 2.0
}
POST _scripts/python/my_script <1>
{
"script": "doc[\"num\"].value * factor"
}
GET test/_search
{
"query": {
"function_score": {
"script_score": {
"script": {
"id": "my_script", <2>
"lang": "python",
"params": {
"factor": 2
}
}
}
}
}
}
----
// CONSOLE
<1> We store the script under the id `my_script`.
<2> The function score query retrieves the script with id `my_script`.
[[lang-python-file]]
[float]
=== File scripts
You can save your scripts to a file in the `config/scripts/` directory on
every node. The `.py` file suffix identifies the script as containing
Python:
First, save this file as `config/scripts/my_script.py` on every node
in the cluster:
[source,python]
----
doc["num"].value * factor
----
then use the script as follows:
[source,js]
----
PUT test/doc/1
{
"num": 1.0
}
PUT test/doc/2
{
"num": 2.0
}
GET test/_search
{
"query": {
"function_score": {
"script_score": {
"script": {
"file": "my_script", <1>
"lang": "python",
"params": {
"factor": 2
}
}
}
}
}
}
----
// CONSOLE
<1> The function score query retrieves the script with filename `my_script.py`.