Datasette class

Many of Datasette’s Plugin hooks pass a datasette object to the plugin as an argument.

This object is an instance of the Datasette class. That class currently has a large number of methods on it, but it should not be considered stable (at least until Datasette 1.0) with the exception of the methods that are documented on this page.

.add_database(name, db)

name - string
The unique name to use for this database. Also used in the URL.
db - datasette.database.Database instance
The database to be attached.

The datasette.add_database(name, db) method lets you add a new database to the current Datasette instance. This database will then be served at URL path that matches the name parameter, e.g. /mynewdb/.

The db parameter should be an instance of the datasette.database.Database class. For example:

from datasette.database import Database

datasette.add_database("my-new-database", Database(

This will add a mutable database from the provided file path.

The Database() constructor takes four arguments: the first is the datasette instance you are attaching to, the second is a path=, then is_mutable and is_memory are both optional arguments.

Use is_mutable if it is possible that updates will be made to that database - otherwise Datasette will open it in immutable mode and any changes could cause undesired behavior.

Use is_memory if the connection is to an in-memory SQLite database.


name - string
The name of the database to be removed.

This removes a database that has been previously added. name= is the unique name of that database, also used in the URL for it.

.plugin_config(plugin_name, database=None, table=None)

plugin_name - string
The name of the plugin to look up configuration for. Usually this is something similar to datasette-cluster-map.
database - None or string
The database the user is interacting with.
table - None or string
The table the user is interacting with.

This method lets you read plugin configuration values that were set in metadata.json. See Writing plugins that accept configuration for full details of how this method should be used.

.render_template(template, context=None, request=None)

template - string
The template file to be rendered, e.g. my_plugin.html. Datasette will search for this file first in the --template-dir= location, if it was specified - then in the plugin’s bundled templates and finally in Datasette’s set of default templates.
conttext - None or a Python dictionary
The context variables to pass to the template.
request - request object or None
If you pass a Datasette request object here it will be made available to the template.

Renders a Jinja template using Datasette’s preconfigured instance of Jinja and returns the resulting string. The template will have access to Datasette’s default template functions and any functions that have been made available by other plugins.