Issue #13690: add re.DEBUG; patch by Filip GruszczyƄski
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index 0c2c4fa..b196a28 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -498,6 +498,11 @@
    isn't allowed for bytes).
 
 
+.. data:: DEBUG
+
+   Display debug information about compiled expression.
+
+
 .. data:: I
           IGNORECASE