grapa.internal.container_metadata.MetadataContainer

class grapa.internal.container_metadata.MetadataContainer(host_curve_or_graph: Graph | Curve)

Bases: object

Container for handling metadata as pairs key-values. It behaves similarly to a dict. Main differences:

• key are str, lower case internally, case insensitive from the outside (historical)

• update({key: VALUE_DEFAULT}) (value “”) does remove the key-value pair

• it is callable (historical reason): obj(key) is equivalent to obj.get(key)

Note: uses the grapa recorder to undo/redo actions. Suggestion to grapa users: it may be advantageous to stick to the methods defined in classes Curve and Graph, which behave consistently: attr(key), update({key: value}), has_attr(key), get_attributes(), attr_pop(key)) It avoids the technicality that Graph constains 2 MetadataContainer objects.

__init__(host_curve_or_graph: Graph | Curve)

Methods

__init__(host_curve_or_graph)
clear()	Remove all items from the container
format(key)	Formats the key.
get(key[, default])	Returns the value associated with key.
has_attr(key)	Returns if a key has been defined.
is_attr_value_default(value)	Test if value corresponds to default value.
items()	to iterate over items
pop(key)	Removes an existing key-value pair.
update(attributes)	Updates attributes.
values([keys_list])	Returns a copied dict of all attributes key-values.

Attributes

VALUE_DEFAULT

clear()

Remove all items from the container

static format(key: str) → str

Formats the key. key must be a str

get(key: str, default='')

Returns the value associated with key. If key not found, returns VALUE_DEFAULT (i.e. not KeyError)

Parameters:

• key – a str

• default – default return value.

Returns:

The value associated with key.

has_attr(key: str) → bool

Returns if a key has been defined.

Parameters:

key – the key of interest

Returns:

True if key is defined and not default, False otherwise

classmethod is_attr_value_default(value) → bool

Test if value corresponds to default value.

Parameters:

value – a value

Returns:

True if val is default value (e.g. not defined), False otherwise

items()

to iterate over items

pop(key: str)

Removes an existing key-value pair. Returns the earlier value, or default if not specified. Does not raise KeyError.

update(attributes: dict) → None

Updates attributes. Some clean-up is performed e.g. key as lower case and strip of characters ` =:\t\r\n`.

Parameters:

attributes – a dict, key-value

values(keys_list: list | None = None)

Returns a copied dict of all attributes key-values.

Parameters:

keys_list – is provided, the returned dict contains only these keys.