Allow Example to align whitespace annotation (#10189)

Remove exception for whitespace tokens in `Example.get_aligned` so that
annotation on whitespace tokens is aligned in the same way as for
non-whitespace tokens.

spacy/tests/training/test_new_example.py

@@ -421,3 +421,13 @@ def test_Example_missing_heads():
     # Ensure that the missing head doesn't create an artificial new sentence start
     expected = [True, False, False, False, False, False]
     assert example.get_aligned_sent_starts() == expected
+
+
+def test_Example_aligned_whitespace(en_vocab):
+    words = ["a", " ", "b"]
+    tags = ["A", "SPACE", "B"]
+    predicted = Doc(en_vocab, words=words)
+    reference = Doc(en_vocab, words=words, tags=tags)
+
+    example = Example(predicted, reference)
+    assert example.get_aligned("TAG", as_string=True) == tags

spacy/training/example.pyx

@@ -159,9 +159,6 @@ cdef class Example:
         gold_values = self.reference.to_array([field])
         output = [None] * len(self.predicted)
         for token in self.predicted:
-            if token.is_space:
-                output[token.i] = None
-            else:
             values = gold_values[align[token.i].dataXd]
             values = values.ravel()
             if len(values) == 0: