[fix] handle case where '._' in 'a._' was recognized as a float

baron/grouper.py

@@ -87,7 +87,7 @@ def group_generator(sequence):
                 current += next(iterator)
 
         if (re.match(r'^[_\d]+$', current) and match_on_next(r'^\.$', iterator)) or\
-           (current == "." and match_on_next(r'^[_\d]+([jJ]|[eE]\d*)?$', iterator)):
+           (current == "." and match_on_next(r'^\d+[_\d]*([jJ]|[eE]\d*)?$', iterator)):
             current += next(iterator)
 
             if match_on_next(r'^[_\d]*[jJ]?$', iterator) and match_on_next(r'^[_\d]*[jJ]?$', iterator).group():

tests/test_grouper.py

@@ -230,3 +230,7 @@ def test_dot_dot():
 
 def test_dot_dot_dot():
     grouper_test("...", ['.', '.', '.'], ['...'])
+
+
+def test_split_float_notation():
+    grouper_test("a._", ["a", ".", "_"], ["a", ".", "_"])

tests/test_regression.py

@@ -1,4 +1,4 @@
-from baron import parse, dumps
+from baron import parse, dumps, tokenize
 
 
 def test_regression_trailing_comment_after_colon():
@@ -22,3 +22,8 @@ def test_regression_trailing_comment_after_colon_no_space_dump():
 def test_comment_in_middle_of_ifelseblock():
     code = 'if a:\n    pass\n# comment\nelse:\n    pass\n'
     assert dumps(parse(code)) == code
+
+
+def test_new_float_notation():
+    code = 'a._'
+    assert tokenize(code)[:-1] == [('NAME', 'a'), ('DOT', '.'), ('NAME', '_')]

tests/test_spliter.py

@@ -373,3 +373,7 @@ def test_regression():
 if python_version == 2:
     def test_remove_crap():
         assert split("\x0c\xef\xbb\xbf") == []
+
+
+def test_split_float_notation():
+    assert split("a._") == ["a", ".", "_"]