diff -r 0a8509023c09 Doc/library/re.rst
--- a/Doc/library/re.rst	Sun Jun 05 01:38:29 2016 +0200
+++ b/Doc/library/re.rst	Sat Jun 04 18:12:30 2016 -0700
@@ -926,6 +926,17 @@
    The pattern string from which the RE object was compiled.
 
 
+.. attribute:: regex.__code__
+
+   The compiled bytecode of the regex, as a string.
+
+   .. impl-detail::
+
+      This attribute is not guaranteed to exist in all implementations of
+      Python. The bytecode returned is an implementation detail that may change
+      without warning between CPython versions.
+
+
 .. _match-objects:
 
 Match Objects
diff -r 0a8509023c09 Lib/test/test_re.py
--- a/Lib/test/test_re.py	Sun Jun 05 01:38:29 2016 +0200
+++ b/Lib/test/test_re.py	Sat Jun 04 18:12:30 2016 -0700
@@ -587,6 +587,12 @@
             p.groupindex['other'] = 0
         self.assertEqual(p.groupindex['other'], 2)
 
+    @cpython_only
+    def test_code(self):
+        pattern = re.compile('foo')
+        # contents are implementation-defined
+        self.assertIsInstance(pattern.__code__, str)
+
     def test_special_escapes(self):
         self.assertEqual(re.search(r"\b(b.)\b",
                                    "abcd abc bcd bx").group(1), "bx")
diff -r 0a8509023c09 Modules/_sre.c
--- a/Modules/_sre.c	Sun Jun 05 01:38:29 2016 +0200
+++ b/Modules/_sre.c	Sat Jun 04 18:12:30 2016 -0700
@@ -1429,13 +1429,21 @@
 
 PyDoc_STRVAR(pattern_doc, "Compiled regular expression objects");
 
-/* PatternObject's 'groupindex' method. */
+/* PatternObject's 'groupindex' attribute. */
 static PyObject *
 pattern_groupindex(PatternObject *self)
 {
     return PyDictProxy_New(self->groupindex);
 }
 
+/* PatternObject's '__code__' attribute. */
+static PyObject *
+pattern_code(PatternObject *self)
+{
+    return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, self->code,
+                                     self->codesize);
+}
+
 static int _validate(PatternObject *self); /* Forward */
 
 /*[clinic input]
@@ -2671,6 +2679,8 @@
 static PyGetSetDef pattern_getset[] = {
     {"groupindex", (getter)pattern_groupindex, (setter)NULL,
       "A dictionary mapping group names to group numbers."},
+    {"__code__", (getter)pattern_code, (setter)NULL,
+      "The pattern's bytecode string."},
     {NULL}  /* Sentinel */
 };