cs.tagset 20200318

Tags and sets of tags.

Latest release 20200318: Note that the TagsOntology stuff is in flux and totally alpha. Tag.prefix_name factory returning a new tag if prefix is not empty, ptherwise self. TagSet.update: accept an optional prefix for inserting "foreign" tags with a distinguishing name prefix. Tag.as_json: turn sets and tuples into lists for encoding. Backport for Python < 3.7 (no fromisoformat functions). TagSet: drop unused and illplaced .titleify, .episode_title and .title methods. TagSet: remove "defaults", unused. Make TagSet a direct subclass of dict, adjust uses of .update etc. New ExtendedNamespace class which is a SimpleNamespace with some inferred attributes and a partial mapping API (keys and getitem). New TagSet.ns() returning the Tags as an ExtendedNamespace, which doubles as a mapping for str.format_map; TagSet.format_kwargs is now an alias for this. New Tag.from_string factory to parse a str into a Tag. New TagsOntology and TypedTag classes to provide type and value-detail information; very very alpha and subject to change.

Tags and sets of tags.

Class ExtendedNamespace(types.SimpleNamespace)

Subclass SimpleNamespace with inferred attributes. This also presents attributes as [] elements via __getitem__.

Class Tag(Tag,builtins.tuple)

A Tag has a .name (str) and a .value.

The name must be a dotted identifier.

A "bare" Tag has a value of None.

Class TagChoice(TagChoice,builtins.tuple)

A "tag choice", an apply/reject flag and a Tag, used to apply changes to a TagSet or as a criterion for a tag search.

Attributes:

• spec: the source text from which this choice was parsed, possibly None
• choice: the apply/reject flag
• tag: the Tag representing the criterion

Class TagSet(builtins.dict,cs.lex.FormatableMixin)

A setlike class associating a set of tag names with values.

Method TagSet.__init__(self)

Initialise the TagSet.

Class TagsOntology(cs.obj.SingletonMixin)

An ontology for tag names.

This is based around a mapping of tag names to ontological information expressed as a TagSet.

A cs.fstags.FSTags uses ontologies initialised from TagFiles containing ontology mappings.

Class TypedTag(cs.lex.FormatableMixin)

A Taglike object linked to a TagOntology, providing associated detail about a Tag.

Like Tag, this has a .name and .value.

Additionally it has the following attributes:

• ontology: the supporting TagOntology
• tag: the originating Tag (computed from the (name,value) tuple if supplied)
• defn: the TagSet from .ontology which defines this
• type: defn['type']
• member_type: defn['member_type'] if present; we expect type to be a list or mapping type name

Indexing a TypedTag indexes its .value and returns a tuple (element,TagSet) where the TagSet is information from the ontology about the element's value (if element is a str).

If the .value looks like a mapping .ie. it has a .keys() method then a TypedTag has .keys() and .items() methods. The .keys() call returns .value.keys(). The .items() call yields (key,self[key]) for each of self.keys().

Iterating over a TypedTag yields its keys if it has a .keys() method, otherwise values from range(len(self.value)).

Method TypedTag.__init__(self, name, value=None, *, ontology)

Prepare the TypedTag from a Tag or (name,value) tuple.

Release Log

Release 20200318: Note that the TagsOntology stuff is in flux and totally alpha. Tag.prefix_name factory returning a new tag if prefix is not empty, ptherwise self. TagSet.update: accept an optional prefix for inserting "foreign" tags with a distinguishing name prefix. Tag.as_json: turn sets and tuples into lists for encoding. Backport for Python < 3.7 (no fromisoformat functions). TagSet: drop unused and illplaced .titleify, .episode_title and .title methods. TagSet: remove "defaults", unused. Make TagSet a direct subclass of dict, adjust uses of .update etc. New ExtendedNamespace class which is a SimpleNamespace with some inferred attributes and a partial mapping API (keys and getitem). New TagSet.ns() returning the Tags as an ExtendedNamespace, which doubles as a mapping for str.format_map; TagSet.format_kwargs is now an alias for this. New Tag.from_string factory to parse a str into a Tag. New TagsOntology and TypedTag classes to provide type and value-detail information; very very alpha and subject to change.

Release 20200229.1: Initial release: pull TagSet, Tag, TagChoice from cs.fstags for independent use.