Fix SpanGroup and Span typing (#12009)

* Correct Span.label, Span.kb_id types. Fix SpanGroup.__iter__().

* Extend test.

* Rename test. Fix typo.

* Add comment.

* Fix types for Span.label, Span.kb_id, Span.char_span().

* Update spacy/tests/doc/test_span_group.py

Co-authored-by: Adriane Boyd <adrianeboyd@gmail.com>

* Update docs.

* Fix typo.

* Update spacy/tokens/span_group.pyx

Co-authored-by: Adriane Boyd <adrianeboyd@gmail.com>

Co-authored-by: Adriane Boyd <adrianeboyd@gmail.com>

spacy/tests/doc/test_span_group.py

@@ -1,7 +1,10 @@
+from typing import List
+
 import pytest
 from random import Random
 from spacy.matcher import Matcher
-from spacy.tokens import Span, SpanGroup
+from spacy.tokens import Span, SpanGroup, Doc
+from spacy.util import filter_spans
 
 
 @pytest.fixture
@@ -240,3 +243,13 @@ def test_span_group_extend(doc):
 def test_span_group_dealloc(span_group):
     with pytest.raises(AttributeError):
         print(span_group.doc)
+
+
+@pytest.mark.issue(11975)
+def test_span_group_typing(doc: Doc):
+    """Tests whether typing of `SpanGroup` as `Iterable[Span]`-like object is accepted by mypy."""
+    span_group: SpanGroup = doc.spans["SPANS"]
+    spans: List[Span] = list(span_group)
+    for i, span in enumerate(span_group):
+        assert span == span_group[i] == spans[i]
+    filter_spans(span_group)

spacy/tokens/span.pyi

@@ -95,8 +95,8 @@ class Span:
         self,
         start_idx: int,
         end_idx: int,
-        label: int = ...,
-        kb_id: int = ...,
+        label: Union[int, str] = ...,
+        kb_id: Union[int, str] = ...,
         vector: Optional[Floats1d] = ...,
     ) -> Span: ...
     @property

spacy/tokens/span_group.pyi

@@ -18,6 +18,7 @@ class SpanGroup:
     def doc(self) -> Doc: ...
     @property
     def has_overlap(self) -> bool: ...
+    def __iter__(self): ...
     def __len__(self) -> int: ...
     def append(self, span: Span) -> None: ...
     def extend(self, spans: Iterable[Span]) -> None: ...

spacy/tokens/span_group.pyx

@@ -158,6 +158,16 @@ cdef class SpanGroup:
             return self._concat(other)
         return NotImplemented
 
+    def __iter__(self):
+        """
+        Iterate over the spans in this SpanGroup.
+        YIELDS (Span): A span in this SpanGroup.
+
+        DOCS: https://spacy.io/api/spangroup#iter
+        """
+        for i in range(self.c.size()):
+            yield self[i]
+
     def append(self, Span span):
         """Add a span to the group. The span must refer to the same Doc
         object as the span group.

website/docs/api/spangroup.md

@@ -202,6 +202,23 @@ already present in the current span group.
 | `other`     | The span group or spans to append. ~~Union[SpanGroup, Iterable[Span]]~~ |
 | **RETURNS** | The span group. ~~SpanGroup~~                                           |
 
+## SpanGroup.\_\_iter\_\_ {#iter tag="method" new="3.5"}
+
+Iterate over the spans in this span group.
+
+> #### Example
+>
+> ```python
+> doc = nlp("Their goi ng home")
+> doc.spans["errors"] = [doc[0:1], doc[1:3]]
+> for error_span in doc.spans["errors"]:
+>     print(error_span)
+> ```
+
+| Name       | Description                         |
+| ---------- | ----------------------------------- |
+| **YIELDS** | A span in this span group. ~~Span~~ |
+
 ## SpanGroup.append {#append tag="method"}
 
 Add a [`Span`](/api/span) object to the group. The span must refer to the same