happi.backends.json_db.JSONBackend

class happi.backends.json_db.JSONBackend(path: str, initialize: bool = False, cfg_path: str | None = None)

JSON database.

The happi information is kept in a single large dictionary that is stored using the simplejson package.

Parameters:

• path (str) – Path to JSON file.

• initialize (bool, optional) – Initialize a new empty JSON file to begin filling.

• cfg_path (str, optional) – Path to the happi config.

__init__(path: str, initialize: bool = False, cfg_path: str | None = None) → None

Methods

__init__(path[, initialize, cfg_path])
clear_cache()	Clear the loaded cache.
delete(_id)	Delete an item instance from the database.
find(to_match)	Find an instance or instances that matches the search criteria.
find_range(key, *, start[, stop])	Find an instance or instances that matches the search criteria, such that start <= entry[key] < stop.
find_regex(to_match, *[, flags])	Find an instance or instances that matches the search criteria, using regular expressions.
get_by_id(id_)	Get an item by ID if it exists, or return None.
initialize()	Initialize a new JSON file database.
load()	Load the JSON database.
save(_id, post[, insert])	Save information to the database.
store(db)	Stash the database in the JSON file.

Attributes

all_items

All of the items in the database.