1 files changed, 22 insertions, 0 deletions
diff --git a/Lib/lib2to3/tests/data/py3_test_grammar.py b/Lib/lib2to3/tests/data/py3_test_grammar.py
index cf31a54..0b9bee0 100644
--- a/Lib/lib2to3/tests/data/py3_test_grammar.py
+++ b/Lib/lib2to3/tests/data/py3_test_grammar.py
@@ -72,6 +72,28 @@ class TokenTests(unittest.TestCase):
         x = 0b100000000000000000000000000000000000000000000000000000000000000000000
         x = 0B111111111111111111111111111111111111111111111111111111111111111111111
 
+    def testUnderscoresInNumbers(self):
+        # Integers
+        x = 1_0
+        x = 123_456_7_89
+        x = 0xabc_123_4_5
+        x = 0X_abc_123
+        x = 0B11_01
+        x = 0b_11_01
+        x = 0o45_67
+        x = 0O_45_67
+
+        # Floats
+        x = 3_1.4
+        x = 03_1.4
+        x = 3_1.
+        x = .3_1
+        x = 3.1_4
+        x = 0_3.1_4
+        x = 3e1_4
+        x = 3_1e+4_1
+        x = 3_1E-4_1
+
     def testFloats(self):
         x = 3.14
         x = 314.