alab_management.device_view.dbattributes module

class DictInDatabase(device_collection, device_name, attribute_name, default_value=None)

Bases: object

Class that emulates a dict, but stores the dict in the device database. Useful for working with Device attributes that are dict, so values persist across alabos sessions. This should be instantiated using alab_management.device_view.device.BaseDevice.dict_in_database.

apply_default_value()

This is called within alab_management.scripts.setup_lab() to ensure that all devices have the correct default values for their attributes. This should not be called manually.

Raises —— ValueError: Device is not found in the database. This should only occur if this function is called out of order (i.e. before the device is created in the db).

as_normal_dict()

Return a normal dict representation of the DictInDatabase. This will not update the database.

Return type:

dict

clear()

Clear the dict. This will update the database with the new value.

copy()

Return a copy of the dict. This will not update the database.

property db_filter

The filter used to retrieve the attribute from the database. This is used internally by the class.

property db_projection

The projection used to retrieve the attribute from the database. This is used internally by the class.

fromkeys()

Return a copy of the dict. This will not update the database.

get(key, default=None)

Return a copy of the dict. This will not update the database.

items()

Return a copy of the dict. This will not update the database.

keys()

Return a copy of the dict. This will not update the database.

pop(key, default='be8b61ee-48b1-4624-bf7a-2ca31f7c5ef4')

Return a copy of the dict. This will not update the database.

popitem()

Return a copy of the dict. This will not update the database.

setdefault(key, default=None)

Return a copy of the dict. This will not update the database.

update(*args, **kwargs)

Return a copy of the dict. This will not update the database.

values()

Return a copy of the dict. This will not update the database.

class ListInDatabase(device_collection, device_name, attribute_name, default_value=None)

Bases: object

Class that emulates a list, but stores the list in the device database. Useful for working with Device attributes that are lists, so values persist across alabos sessions. This should be instantiated using alab_management.device_view.device.BaseDevice.list_in_database.

append(x)

Append an element to the list. This will update the database with the new value.

apply_default_value()

This is called within alab_management.scripts.setup_lab() to ensure that all devices have the correct default values for their attributes. This should not be called manually.

Raises —— ValueError: Device is not found in the database. This should only occur if this function is called out of order (i.e. before the device is created in the db).

clear()

Clear the list. This will update the database with the new value.

copy()

Return a copy of the list. This will not update the database.

count()

Return the number of occurrences of x in the list. This will not update the database.

property db_filter

The filter used to retrieve the attribute from the database. This is used internally by the class.

property db_projection

The projection used to retrieve the attribute from the database. This is used internally by the class.

extend(x)

Extend the list with another iterable. This will update the database with the new value.

index(x, start=None, stop=None)

Return the index of the first occurrence of x in the list. This will not update the database.

insert(i, x)

Insert an element at a given position. This will update the database with the new value.

pop(i=-1)

Remove the element at a given position. This will update the database with the new value.

remove(x)

Remove the first item from the list whose value is equal to x. This will update the database with the new.

reverse()

Reverse the elements of the list in place. This will update the database with the new value.

sort(key=None, reverse=False)

Sort the items of the list in place. This will update the database with the new value.

value_in_database(name, default_value)

Property factory to mirror a Device attribute in the ALab database. This must be declared as a Class Variable under a Device subclass of BaseDevice!.

Args: name (str): attribute name default_value (Any): default value for the attribute. Note that this value is not used until the first time a property is queried; at this time, if the attribute is not found in the database, it is set to this value.

Return type:

property

Returns:

property: class property that handles getting/setting values from the database.

Example usage when defining a new Device:

from alab_management.device_view import BaseDevice, value_in_database

class MyDevice(BaseDevice):
    my_attribute = value_in_database("my_attribute", 0)

    def __init__(self, name: str, **kwargs):
        super().__init__(name, **kwargs)
        self.name = name
        self.my_attribute #initial call to the property, which sets the default value in the database

....
#first instantiation

mydevice = MyDevice(name = "mydevice_1")
mydevice.my_attribute = 5 #sets the value in the database

....
#future instantiation
mydevice = MyDevice(name = "mydevice_1")
mydevice.my_attribute #retrieves value from db and returns 5