fix: raise ValueError instead of UnboundLocalError in _get_indexed_match on zero matches

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Fixes
 
 - **Update README.md**: readme-only changes; added a link to Unstructured Pipelines to the README. No library behavior changes.
+- **`_get_indexed_match` raises `ValueError` instead of `UnboundLocalError` on zero matches**: `extract_text_before()`/`extract_text_after()`'s underlying helper looped `for i, result in enumerate(re.finditer(pattern, text))` and referenced `i` in its "not found" error message; when the pattern matched zero times, the loop body never ran, so `i` was never bound, raising `UnboundLocalError` instead of the intended `ValueError`. `i` is now initialized to `-1` before the loop.
 
 ## 0.25.0
 

test_unstructured/cleaners/test_extract.py

@@ -19,6 +19,16 @@ def test_get_indexed_match_raises_with_index_too_high():
         extract._get_indexed_match("BLAH BLAH BLAH", "BLAH", 4)
 
 
+def test_get_indexed_match_raises_value_error_with_zero_matches():
+    """Regression test: when the pattern has zero matches at all (not just an
+    out-of-range index on an otherwise-matching pattern), the "not found" branch
+    referenced the loop variable `i`, which Python never binds when a for-loop's
+    iterable is empty -- raising UnboundLocalError instead of the intended
+    ValueError."""
+    with pytest.raises(ValueError):
+        extract._get_indexed_match("no digits here", r"[0-9]+")
+
+
 def test_extract_text_before():
     text = "Teacher: BLAH BLAH BLAH; Student: BLAH BLAH BLAH!"
     assert extract.extract_text_before(text, "BLAH", 1) == "Teacher: BLAH"

unstructured/cleaners/extract.py

@@ -18,6 +18,7 @@ def _get_indexed_match(text: str, pattern: str, index: int = 0) -> re.Match:
         raise ValueError(f"The index is {index}. Index must be a non-negative integer.")
 
     regex_match = None
+    i = -1
     for i, result in enumerate(re.finditer(pattern, text)):
         if i == index:
             regex_match = result