Keep keyword before leading-dot float literal (issue #601)

CHANGELOG

@@ -41,6 +41,10 @@ Bug Fixes
 * Recognize ``MATERIALIZED`` as a keyword so it is parsed and formatted
   consistently in ``CREATE MATERIALIZED VIEW`` statements (issue752).
 * Fix ``get_real_name`` for names with more than two dotted parts (issue332).
+* Keep a keyword such as ``BETWEEN`` from being reclassified as an identifier
+  when it is followed by a float literal written without a leading zero
+  (e.g. ``x BETWEEN .03 AND .06``), so the bounds are parsed as number tokens
+  (issue601).
 
 
 Release 0.5.5 (Dec 19, 2025)

sqlparse/keywords.py

@@ -49,7 +49,11 @@
     # see issue #39
     # Spaces around period `schema . name` are valid identifier
     # TODO: Spaces before period not implemented
-    (r'[A-ZÀ-Ü]\w*(?=\s*\.)', tokens.Name),  # 'Name'.
+    # The negative lookahead ``(?!\d)`` keeps a following floating point
+    # literal such as ``.03`` from being mistaken for a member access, so a
+    # preceding keyword (e.g. ``BETWEEN``) is not reclassified as a name.
+    # See issue #601.
+    (r'[A-ZÀ-Ü]\w*(?=\s*\.(?!\d))', tokens.Name),  # 'Name'.
     # FIXME(atronah): never match,
     # because `re.match` doesn't work with look-behind regexp feature
     (r'(?<=\.)[A-ZÀ-Ü]\w*', tokens.Name),  # .'Name'

tests/test_regressions.py

@@ -477,6 +477,34 @@ def test_materialized_view_issue752():
     assert formatted == 'CREATE MATERIALIZED VIEW v AS SELECT 1'
 
 
+@pytest.mark.parametrize('sql', [
+    'a BETWEEN .03 AND .06',
+    'a between .03 and .06',
+])
+def test_between_leading_dot_float_issue601(sql):
+    # A keyword followed by a float literal written without a leading zero
+    # (e.g. ``.03``) must not be reclassified as an identifier because of the
+    # following period.  BETWEEN has to stay a keyword and the literals have to
+    # remain standalone number tokens.
+    p = sqlparse.parse(sql)[0]
+    kw = p.token_next_by(m=(T.Keyword, 'BETWEEN'))[1]
+    assert kw is not None
+    floats = list(p.flatten())
+    floats = [t for t in floats if t.ttype is T.Number.Float]
+    assert [t.value for t in floats] == ['.03', '.06']
+    # 'and' must remain a keyword too, not be absorbed into an identifier.
+    assert p.token_next_by(m=(T.Keyword, 'AND'))[1] is not None
+
+
+def test_keyword_before_qualified_name_still_grouped():
+    # Regression guard for issue #601 fix: member access such as
+    # ``schema.name`` (with or without surrounding spaces) must keep working.
+    for stmt in ('select foo.bar', 'select foo . bar', 'select a.b.c'):
+        p = sqlparse.parse(stmt)[0]
+        ident = p.token_next_by(i=sql.Identifier)[1]
+        assert ident is not None
+
+
 @pytest.fixture
 def limit_recursion():
     curr_limit = sys.getrecursionlimit()