Override SpanGroups.setdefault to provide default SpanGroup (#10772)

* Fix mistake in SpanGroup API docs

* Restrict SpanGroups.setdefault to SpanGroup only

* Refactor to support default span iterable

spacy/tests/doc/test_doc_api.py

@@ -11,7 +11,7 @@ from spacy.lang.en import English
 from spacy.lang.xx import MultiLanguage
 from spacy.language import Language
 from spacy.lexeme import Lexeme
-from spacy.tokens import Doc, Span, Token
+from spacy.tokens import Doc, Span, SpanGroup, Token
 from spacy.vocab import Vocab
 
 from .test_underscore import clean_underscore  # noqa: F401
@@ -964,3 +964,13 @@ def test_doc_spans_copy(en_tokenizer):
     assert weakref.ref(doc1) == doc1.spans.doc_ref
     doc2 = doc1.copy()
     assert weakref.ref(doc2) == doc2.spans.doc_ref
+
+
+def test_doc_spans_setdefault(en_tokenizer):
+    doc = en_tokenizer("Some text about Colombia and the Czech Republic")
+    doc.spans.setdefault("key1")
+    assert len(doc.spans["key1"]) == 0
+    doc.spans.setdefault("key2", default=[doc[0:1]])
+    assert len(doc.spans["key2"]) == 1
+    doc.spans.setdefault("key3", default=SpanGroup(doc, spans=[doc[0:1], doc[1:2]]))
+    assert len(doc.spans["key3"]) == 2

spacy/tokens/_dict_proxies.py

@@ -43,6 +43,15 @@ class SpanGroups(UserDict):
             doc = self._ensure_doc()
         return SpanGroups(doc).from_bytes(self.to_bytes())
 
+    def setdefault(self, key, default=None):
+        if not isinstance(default, SpanGroup):
+            if default is None:
+                spans = []
+            else:
+                spans = default
+            default = self._make_span_group(key, spans)
+        return super().setdefault(key, default=default)
+
     def to_bytes(self) -> bytes:
         # We don't need to serialize this as a dict, because the groups
         # know their names.

website/docs/api/spangroup.md

@@ -233,7 +233,7 @@ group.
 > doc.spans["errors"] = []
 > doc.spans["errors"].extend([doc[1:3], doc[0:1]])
 > assert len(doc.spans["errors"]) == 2
-> span_group = SpanGroup([doc[1:4], doc[0:3])
+> span_group = SpanGroup(doc, spans=[doc[1:4], doc[0:3]])
 > doc.spans["errors"].extend(span_group)
 > ```