diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 1dbd9ae..281e354 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -197,6 +197,17 @@
         "elt",
         "generators",
 };
+static PyTypeObject *SetComp_type;
+static char *SetComp_fields[]={
+        "elt",
+        "generators",
+};
+static PyTypeObject *DictComp_type;
+static char *DictComp_fields[]={
+        "key",
+        "value",
+        "generators",
+};
 static PyTypeObject *GeneratorExp_type;
 static char *GeneratorExp_fields[]={
         "elt",
@@ -726,6 +737,10 @@
         if (!Set_type) return 0;
         ListComp_type = make_type("ListComp", expr_type, ListComp_fields, 2);
         if (!ListComp_type) return 0;
+        SetComp_type = make_type("SetComp", expr_type, SetComp_fields, 2);
+        if (!SetComp_type) return 0;
+        DictComp_type = make_type("DictComp", expr_type, DictComp_fields, 3);
+        if (!DictComp_type) return 0;
         GeneratorExp_type = make_type("GeneratorExp", expr_type,
                                       GeneratorExp_fields, 2);
         if (!GeneratorExp_type) return 0;
@@ -1631,6 +1646,54 @@
 }
 
 expr_ty
+SetComp(expr_ty elt, asdl_seq * generators, int lineno, int col_offset, PyArena
+        *arena)
+{
+        expr_ty p;
+        if (!elt) {
+                PyErr_SetString(PyExc_ValueError,
+                                "field elt is required for SetComp");
+                return NULL;
+        }
+        p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
+        if (!p)
+                return NULL;
+        p->kind = SetComp_kind;
+        p->v.SetComp.elt = elt;
+        p->v.SetComp.generators = generators;
+        p->lineno = lineno;
+        p->col_offset = col_offset;
+        return p;
+}
+
+expr_ty
+DictComp(expr_ty key, expr_ty value, asdl_seq * generators, int lineno, int
+         col_offset, PyArena *arena)
+{
+        expr_ty p;
+        if (!key) {
+                PyErr_SetString(PyExc_ValueError,
+                                "field key is required for DictComp");
+                return NULL;
+        }
+        if (!value) {
+                PyErr_SetString(PyExc_ValueError,
+                                "field value is required for DictComp");
+                return NULL;
+        }
+        p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
+        if (!p)
+                return NULL;
+        p->kind = DictComp_kind;
+        p->v.DictComp.key = key;
+        p->v.DictComp.value = value;
+        p->v.DictComp.generators = generators;
+        p->lineno = lineno;
+        p->col_offset = col_offset;
+        return p;
+}
+
+expr_ty
 GeneratorExp(expr_ty elt, asdl_seq * generators, int lineno, int col_offset,
              PyArena *arena)
 {
@@ -2610,6 +2673,41 @@
                         goto failed;
                 Py_DECREF(value);
                 break;
+        case SetComp_kind:
+                result = PyType_GenericNew(SetComp_type, NULL, NULL);
+                if (!result) goto failed;
+                value = ast2obj_expr(o->v.SetComp.elt);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "elt", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                value = ast2obj_list(o->v.SetComp.generators,
+                                     ast2obj_comprehension);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "generators", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                break;
+        case DictComp_kind:
+                result = PyType_GenericNew(DictComp_type, NULL, NULL);
+                if (!result) goto failed;
+                value = ast2obj_expr(o->v.DictComp.key);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "key", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                value = ast2obj_expr(o->v.DictComp.value);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "value", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                value = ast2obj_list(o->v.DictComp.generators,
+                                     ast2obj_comprehension);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "generators", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                break;
         case GeneratorExp_kind:
                 result = PyType_GenericNew(GeneratorExp_type, NULL, NULL);
                 if (!result) goto failed;
@@ -4974,6 +5072,118 @@
                 if (*out == NULL) goto failed;
                 return 0;
         }
+        isinstance = PyObject_IsInstance(obj, (PyObject*)SetComp_type);
+        if (isinstance == -1) {
+                return 1;
+        }
+        if (isinstance) {
+                expr_ty elt;
+                asdl_seq* generators;
+
+                if (PyObject_HasAttrString(obj, "elt")) {
+                        int res;
+                        tmp = PyObject_GetAttrString(obj, "elt");
+                        if (tmp == NULL) goto failed;
+                        res = obj2ast_expr(tmp, &elt, arena);
+                        if (res != 0) goto failed;
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"elt\" missing from SetComp");
+                        return 1;
+                }
+                if (PyObject_HasAttrString(obj, "generators")) {
+                        int res;
+                        Py_ssize_t len;
+                        Py_ssize_t i;
+                        tmp = PyObject_GetAttrString(obj, "generators");
+                        if (tmp == NULL) goto failed;
+                        if (!PyList_Check(tmp)) {
+                                PyErr_Format(PyExc_TypeError, "SetComp field \"generators\" must be a list, not a %.200s", tmp->ob_type->tp_name);
+                                goto failed;
+                        }
+                        len = PyList_GET_SIZE(tmp);
+                        generators = asdl_seq_new(len, arena);
+                        if (generators == NULL) goto failed;
+                        for (i = 0; i < len; i++) {
+                                comprehension_ty value;
+                                res = obj2ast_comprehension(PyList_GET_ITEM(tmp, i), &value, arena);
+                                if (res != 0) goto failed;
+                                asdl_seq_SET(generators, i, value);
+                        }
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from SetComp");
+                        return 1;
+                }
+                *out = SetComp(elt, generators, lineno, col_offset, arena);
+                if (*out == NULL) goto failed;
+                return 0;
+        }
+        isinstance = PyObject_IsInstance(obj, (PyObject*)DictComp_type);
+        if (isinstance == -1) {
+                return 1;
+        }
+        if (isinstance) {
+                expr_ty key;
+                expr_ty value;
+                asdl_seq* generators;
+
+                if (PyObject_HasAttrString(obj, "key")) {
+                        int res;
+                        tmp = PyObject_GetAttrString(obj, "key");
+                        if (tmp == NULL) goto failed;
+                        res = obj2ast_expr(tmp, &key, arena);
+                        if (res != 0) goto failed;
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"key\" missing from DictComp");
+                        return 1;
+                }
+                if (PyObject_HasAttrString(obj, "value")) {
+                        int res;
+                        tmp = PyObject_GetAttrString(obj, "value");
+                        if (tmp == NULL) goto failed;
+                        res = obj2ast_expr(tmp, &value, arena);
+                        if (res != 0) goto failed;
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"value\" missing from DictComp");
+                        return 1;
+                }
+                if (PyObject_HasAttrString(obj, "generators")) {
+                        int res;
+                        Py_ssize_t len;
+                        Py_ssize_t i;
+                        tmp = PyObject_GetAttrString(obj, "generators");
+                        if (tmp == NULL) goto failed;
+                        if (!PyList_Check(tmp)) {
+                                PyErr_Format(PyExc_TypeError, "DictComp field \"generators\" must be a list, not a %.200s", tmp->ob_type->tp_name);
+                                goto failed;
+                        }
+                        len = PyList_GET_SIZE(tmp);
+                        generators = asdl_seq_new(len, arena);
+                        if (generators == NULL) goto failed;
+                        for (i = 0; i < len; i++) {
+                                comprehension_ty value;
+                                res = obj2ast_comprehension(PyList_GET_ITEM(tmp, i), &value, arena);
+                                if (res != 0) goto failed;
+                                asdl_seq_SET(generators, i, value);
+                        }
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from DictComp");
+                        return 1;
+                }
+                *out = DictComp(key, value, generators, lineno, col_offset,
+                                arena);
+                if (*out == NULL) goto failed;
+                return 0;
+        }
         isinstance = PyObject_IsInstance(obj, (PyObject*)GeneratorExp_type);
         if (isinstance == -1) {
                 return 1;
@@ -6419,6 +6629,10 @@
         if (PyDict_SetItemString(d, "Set", (PyObject*)Set_type) < 0) return;
         if (PyDict_SetItemString(d, "ListComp", (PyObject*)ListComp_type) < 0)
             return;
+        if (PyDict_SetItemString(d, "SetComp", (PyObject*)SetComp_type) < 0)
+            return;
+        if (PyDict_SetItemString(d, "DictComp", (PyObject*)DictComp_type) < 0)
+            return;
         if (PyDict_SetItemString(d, "GeneratorExp",
             (PyObject*)GeneratorExp_type) < 0) return;
         if (PyDict_SetItemString(d, "Yield", (PyObject*)Yield_type) < 0) return;
diff --git a/Python/ast.c b/Python/ast.c
index 01d1f7a..c76014a 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -31,7 +31,7 @@
                                   expr_context_ty);
 static expr_ty ast_for_testlist(struct compiling *, const node *);
 static stmt_ty ast_for_classdef(struct compiling *, const node *, asdl_seq *);
-static expr_ty ast_for_testlist_gexp(struct compiling *, const node *);
+static expr_ty ast_for_testlist_comp(struct compiling *, const node *);
 
 /* Note different signature for ast_for_call */
 static expr_ty ast_for_call(struct compiling *, const node *, expr_ty);
@@ -44,6 +44,9 @@
 #define LINENO(n)       ((n)->n_lineno)
 #endif
 
+#define COMP_GENEXP 0
+#define COMP_SETCOMP  1
+
 static identifier
 new_identifier(const char* n, PyArena *arena) {
     PyObject* id = PyString_InternFromString(n);
@@ -268,7 +271,7 @@
         case eval_input: {
             expr_ty testlist_ast;
 
-            /* XXX Why not gen_for here? */
+            /* XXX Why not comp_for here? */
             testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
             if (!testlist_ast)
                 goto error;
@@ -430,6 +433,12 @@
         case ListComp_kind:
             expr_name = "list comprehension";
             break;
+        case SetComp_kind:
+            expr_name = "set comprehension";
+            break;
+        case DictComp_kind:
+            expr_name = "dict comprehension";
+            break;
         case Dict_kind:
         case Num_kind:
         case Str_kind:
@@ -573,7 +582,7 @@
     int i;
     assert(TYPE(n) == testlist ||
            TYPE(n) == listmaker ||
-           TYPE(n) == testlist_gexp ||
+           TYPE(n) == testlist_comp ||
            TYPE(n) == testlist_safe ||
            TYPE(n) == testlist1);
 
@@ -1150,60 +1159,60 @@
     return ListComp(elt, listcomps, LINENO(n), n->n_col_offset, c->c_arena);
 }
 
-/* Count the number of 'for' loops in a generator expression.
+/*
+   Count the number of 'for' loops in a comprehension.
 
-   Helper for ast_for_genexp().
+   Helper for ast_for_comprehension().
 */
 
 static int
-count_gen_fors(struct compiling *c, const node *n)
+count_comp_fors(struct compiling *c, const node *n)
 {
     int n_fors = 0;
-    node *ch = CHILD(n, 1);
 
- count_gen_for:
+  count_comp_for:
     n_fors++;
-    REQ(ch, gen_for);
-    if (NCH(ch) == 5)
-        ch = CHILD(ch, 4);
+    REQ(n, comp_for);
+    if (NCH(n) == 5)
+        n = CHILD(n, 4);
     else
         return n_fors;
- count_gen_iter:
-    REQ(ch, gen_iter);
-    ch = CHILD(ch, 0);
-    if (TYPE(ch) == gen_for)
-        goto count_gen_for;
-    else if (TYPE(ch) == gen_if) {
-        if (NCH(ch) == 3) {
-            ch = CHILD(ch, 2);
-            goto count_gen_iter;
+  count_comp_iter:
+    REQ(n, comp_iter);
+    n = CHILD(n, 0);
+    if (TYPE(n) == comp_for)
+        goto count_comp_for;
+    else if (TYPE(n) == comp_if) {
+        if (NCH(n) == 3) {
+            n = CHILD(n, 2);
+            goto count_comp_iter;
         }
         else
             return n_fors;
     }
-    
+
     /* Should never be reached */
     PyErr_SetString(PyExc_SystemError,
-                    "logic error in count_gen_fors");
+                    "logic error in count_comp_fors");
     return -1;
 }
 
-/* Count the number of 'if' statements in a generator expression.
+/* Count the number of 'if' statements in a comprehension.
 
-   Helper for ast_for_genexp().
+   Helper for ast_for_comprehension().
 */
 
 static int
-count_gen_ifs(struct compiling *c, const node *n)
+count_comp_ifs(struct compiling *c, const node *n)
 {
     int n_ifs = 0;
 
     while (1) {
-        REQ(n, gen_iter);
-        if (TYPE(CHILD(n, 0)) == gen_for)
+        REQ(n, comp_iter);
+        if (TYPE(CHILD(n, 0)) == comp_for)
             return n_ifs;
         n = CHILD(n, 0);
-        REQ(n, gen_if);
+        REQ(n, comp_if);
         n_ifs++;
         if (NCH(n) == 2)
             return n_ifs;
@@ -1211,46 +1220,33 @@
     }
 }
 
-/* TODO(jhylton): Combine with list comprehension code? */
-static expr_ty
-ast_for_genexp(struct compiling *c, const node *n)
+static asdl_seq *
+ast_for_comprehension(struct compiling *c, const node *n)
 {
-    /* testlist_gexp: test ( gen_for | (',' test)* [','] )
-       argument: [test '='] test [gen_for]       # Really [keyword '='] test */
-    expr_ty elt;
-    asdl_seq *genexps;
     int i, n_fors;
-    node *ch;
-    
-    assert(TYPE(n) == (testlist_gexp) || TYPE(n) == (argument));
-    assert(NCH(n) > 1);
-    
-    elt = ast_for_expr(c, CHILD(n, 0));
-    if (!elt)
-        return NULL;
-    
-    n_fors = count_gen_fors(c, n);
+    asdl_seq *comps;
+
+    n_fors = count_comp_fors(c, n);
     if (n_fors == -1)
         return NULL;
 
-    genexps = asdl_seq_new(n_fors, c->c_arena);
-    if (!genexps)
+    comps = asdl_seq_new(n_fors, c->c_arena);
+    if (!comps)
         return NULL;
 
-    ch = CHILD(n, 1);
     for (i = 0; i < n_fors; i++) {
-        comprehension_ty ge;
+        comprehension_ty comp;
         asdl_seq *t;
         expr_ty expression, first;
         node *for_ch;
         
-        REQ(ch, gen_for);
+        REQ(n, comp_for);
         
-        for_ch = CHILD(ch, 1);
+        for_ch = CHILD(n, 1);
         t = ast_for_exprlist(c, for_ch, Store);
         if (!t)
             return NULL;
-        expression = ast_for_expr(c, CHILD(ch, 3));
+        expression = ast_for_expr(c, CHILD(n, 3));
         if (!expression)
             return NULL;
 
@@ -1258,21 +1254,20 @@
            (x for x, in ...) has 1 element in t, but still requires a Tuple. */
         first = (expr_ty)asdl_seq_GET(t, 0);
         if (NCH(for_ch) == 1)
-            ge = comprehension(first, expression, NULL, c->c_arena);
+            comp = comprehension(first, expression, NULL, c->c_arena);
         else
-            ge = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
+            comp = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
                                      c->c_arena),
                                expression, NULL, c->c_arena);
-
-        if (!ge)
+        if (!comp)
             return NULL;
 
-        if (NCH(ch) == 5) {
+        if (NCH(n) == 5) {
             int j, n_ifs;
             asdl_seq *ifs;
             
-            ch = CHILD(ch, 4);
-            n_ifs = count_gen_ifs(c, ch);
+            n = CHILD(n, 4);
+            n_ifs = count_comp_ifs(c, n);
             if (n_ifs == -1)
                 return NULL;
 
@@ -1281,32 +1276,94 @@
                 return NULL;
 
             for (j = 0; j < n_ifs; j++) {
-                REQ(ch, gen_iter);
-                ch = CHILD(ch, 0);
-                REQ(ch, gen_if);
+                REQ(n, comp_iter);
+                n = CHILD(n, 0);
+                REQ(n, comp_if);
                 
-                expression = ast_for_expr(c, CHILD(ch, 1));
+                expression = ast_for_expr(c, CHILD(n, 1));
                 if (!expression)
                     return NULL;
                 asdl_seq_SET(ifs, j, expression);
-                if (NCH(ch) == 3)
-                    ch = CHILD(ch, 2);
+                if (NCH(n) == 3)
+                    n = CHILD(n, 2);
             }
-            /* on exit, must guarantee that ch is a gen_for */
-            if (TYPE(ch) == gen_iter)
-                ch = CHILD(ch, 0);
-            ge->ifs = ifs;
+            /* on exit, must guarantee that n is a comp_for */
+            if (TYPE(n) == comp_iter)
+                n = CHILD(n, 0);
+            comp->ifs = ifs;
         }
-        asdl_seq_SET(genexps, i, ge);
+        asdl_seq_SET(comps, i, comp);
     }
+    return comps;
+}
+
+static expr_ty
+ast_for_itercomp(struct compiling *c, const node *n, int type)
+{
+    expr_ty elt;
+    asdl_seq *comps;
     
-    return GeneratorExp(elt, genexps, LINENO(n), n->n_col_offset, c->c_arena);
+    assert(NCH(n) > 1);
+    
+    elt = ast_for_expr(c, CHILD(n, 0));
+    if (!elt)
+        return NULL;
+    
+    comps = ast_for_comprehension(c, CHILD(n, 1));
+    if (!comps)
+        return NULL;
+
+    if (type == COMP_GENEXP)
+        return GeneratorExp(elt, comps, LINENO(n), n->n_col_offset, c->c_arena);
+    else if (type == COMP_SETCOMP)
+        return SetComp(elt, comps, LINENO(n), n->n_col_offset, c->c_arena);
+    else
+        /* Should never happen */
+        return NULL;
+}
+
+static expr_ty
+ast_for_dictcomp(struct compiling *c, const node *n)
+{
+    expr_ty key, value;
+    asdl_seq *comps;
+    
+    assert(NCH(n) > 3);
+    REQ(CHILD(n, 1), COLON);
+    
+    key = ast_for_expr(c, CHILD(n, 0));
+    if (!key)
+        return NULL;
+
+    value = ast_for_expr(c, CHILD(n, 2));
+    if (!value)
+        return NULL;
+    
+    comps = ast_for_comprehension(c, CHILD(n, 3));
+    if (!comps)
+        return NULL;
+    
+    return DictComp(key, value, comps, LINENO(n), n->n_col_offset, c->c_arena);
+}
+
+static expr_ty
+ast_for_genexp(struct compiling *c, const node *n)
+{
+    assert(TYPE(n) == (testlist_comp) || TYPE(n) == (argument));
+    return ast_for_itercomp(c, n, COMP_GENEXP);
+}
+
+static expr_ty
+ast_for_setcomp(struct compiling *c, const node *n)
+{
+    assert(TYPE(n) == (dictorsetmaker));
+    return ast_for_itercomp(c, n, COMP_SETCOMP);
 }
 
 static expr_ty
 ast_for_atom(struct compiling *c, const node *n)
 {
-    /* atom: '(' [yield_expr|testlist_gexp] ')' | '[' [listmaker] ']'
+    /* atom: '(' [yield_expr|testlist_comp] ')' | '[' [listmaker] ']'
        | '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING+
     */
     node *ch = CHILD(n, 0);
@@ -1365,7 +1422,7 @@
         if (TYPE(ch) == yield_expr)
             return ast_for_expr(c, ch);
         
-        return ast_for_testlist_gexp(c, ch);
+        return ast_for_testlist_comp(c, ch);
     case LSQB: /* list (or list comprehension) */
         ch = CHILD(n, 1);
         
@@ -1383,8 +1440,9 @@
         else
             return ast_for_listcomp(c, ch);
     case LBRACE: {
-        /* dictorsetmaker: test ':' test (',' test ':' test)* [','] |
-         *                 test (',' test)* [','])
+        /* dictorsetmaker:
+         *    (test ':' test (comp_for | (',' test ':' test)* [','])) |
+         *    (test (comp_for | (',' test)* [',']))
          */
         int i, size;
         asdl_seq *keys, *values;
@@ -1408,6 +1466,11 @@
                 asdl_seq_SET(elts, i / 2, expression);
             }
             return Set(elts, LINENO(n), n->n_col_offset, c->c_arena);
+        } else if (TYPE(CHILD(ch, 1)) == comp_for) {
+            /* it's a set comprehension */
+            return ast_for_setcomp(c, ch);
+        } else if (NCH(ch) > 3 && TYPE(CHILD(ch, 3)) == comp_for) {
+            return ast_for_dictcomp(c, ch);
         } else {
             /* it's a dict */
             size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
@@ -1916,7 +1979,7 @@
     /*
       arglist: (argument ',')* (argument [',']| '*' test [',' '**' test]
                | '**' test)
-      argument: [test '='] test [gen_for]        # Really [keyword '='] test
+      argument: [test '='] test [comp_for]        # Really [keyword '='] test
     */
 
     int i, nargs, nkeywords, ngens;
@@ -1934,7 +1997,7 @@
         if (TYPE(ch) == argument) {
             if (NCH(ch) == 1)
                 nargs++;
-            else if (TYPE(CHILD(ch, 1)) == gen_for)
+            else if (TYPE(CHILD(ch, 1)) == comp_for)
                 ngens++;
             else
                 nkeywords++;
@@ -1979,7 +2042,7 @@
                     return NULL;
                 asdl_seq_SET(args, nargs++, e);
             }  
-            else if (TYPE(CHILD(ch, 1)) == gen_for) {
+            else if (TYPE(CHILD(ch, 1)) == comp_for) {
                 e = ast_for_genexp(c, ch);
                 if (!e)
                     return NULL;
@@ -2049,14 +2112,14 @@
 static expr_ty
 ast_for_testlist(struct compiling *c, const node* n)
 {
-    /* testlist_gexp: test (',' test)* [','] */
+    /* testlist_comp: test (',' test)* [','] */
     /* testlist: test (',' test)* [','] */
     /* testlist_safe: test (',' test)+ [','] */
     /* testlist1: test (',' test)* */
     assert(NCH(n) > 0);
-    if (TYPE(n) == testlist_gexp) {
+    if (TYPE(n) == testlist_comp) {
         if (NCH(n) > 1)
-            assert(TYPE(CHILD(n, 1)) != gen_for);
+            assert(TYPE(CHILD(n, 1)) != comp_for);
     }
     else {
         assert(TYPE(n) == testlist ||
@@ -2074,12 +2137,12 @@
 }
 
 static expr_ty
-ast_for_testlist_gexp(struct compiling *c, const node* n)
+ast_for_testlist_comp(struct compiling *c, const node* n)
 {
-    /* testlist_gexp: test ( gen_for | (',' test)* [','] ) */
-    /* argument: test [ gen_for ] */
-    assert(TYPE(n) == testlist_gexp || TYPE(n) == argument);
-    if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == gen_for)
+    /* testlist_comp: test ( comp_for | (',' test)* [','] ) */
+    /* argument: test [ comp_for ] */
+    assert(TYPE(n) == testlist_comp || TYPE(n) == argument);
+    if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == comp_for)
         return ast_for_genexp(c, n);
     return ast_for_testlist(c, n);
 }
diff --git a/Python/ceval.c b/Python/ceval.c
index 3221ab1..d501a4e 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1455,6 +1455,17 @@
 			}
 			break;
 
+		case SET_ADD:
+			w = POP();
+			v = stack_pointer[-oparg];
+			err = PySet_Add(v, w);
+			Py_DECREF(w);
+			if (err == 0) {
+				PREDICT(JUMP_ABSOLUTE);
+				continue;
+			}
+			break;
+
 		case INPLACE_POWER:
 			w = POP();
 			v = TOP();
@@ -2223,6 +2234,21 @@
 			if (err == 0) continue;
 			break;
 
+		case MAP_ADD:
+			w = TOP();     /* key */
+			u = SECOND();  /* value */
+			STACKADJ(-2);
+			v = stack_pointer[-oparg];  /* dict */
+			assert (PyDict_CheckExact(v));
+			err = PyDict_SetItem(v, w, u);  /* v[w] = u */
+			Py_DECREF(u);
+			Py_DECREF(w);
+			if (err == 0) {
+				PREDICT(JUMP_ABSOLUTE);
+				continue;
+			}
+			break;
+
 		case LOAD_ATTR:
 			w = GETITEM(names, oparg);
 			v = TOP();
diff --git a/Python/compile.c b/Python/compile.c
index c8cab1c..1e27539 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -39,6 +39,10 @@
 #define DEFAULT_CODE_SIZE 128
 #define DEFAULT_LNOTAB_SIZE 16
 
+#define COMP_GENEXP   0
+#define COMP_SETCOMP  1
+#define COMP_DICTCOMP 2
+
 struct instr {
 	unsigned i_jabs : 1;
 	unsigned i_jrel : 1;
@@ -674,9 +678,13 @@
 		case UNARY_INVERT:
 			return 0;
 
+		case SET_ADD:
 		case LIST_APPEND:
 			return -1;
 
+		case MAP_ADD:
+			return -2;
+
 		case BINARY_POWER:
 		case BINARY_MULTIPLY:
 		case BINARY_DIVIDE:
@@ -2639,33 +2647,44 @@
 					   e->v.ListComp.elt);
 }
 
+/* Dict and set comprehensions and generator expressions work by creating a
+   nested function to perform the actual iteration. This means that the
+   iteration variables don't leak into the current scope.
+   The defined function is called immediately following its definition, with the
+   result of that call being the result of the expression.
+   The LC/SC version returns the populated container, while the GE version is
+   flagged in symtable.c as a generator, so it returns the generator object
+   when the function is called.
+   This code *knows* that the loop cannot contain break, continue, or return,
+   so it cheats and skips the SETUP_LOOP/POP_BLOCK steps used in normal loops.
+
+   Possible cleanups:
+    - iterate over the generator sequence instead of using recursion
+*/
+
 static int
-compiler_genexp_generator(struct compiler *c,
-			  asdl_seq *generators, int gen_index, 
-			  expr_ty elt)
+compiler_comprehension_generator(struct compiler *c, 
+				 asdl_seq *generators, int gen_index, 
+				 expr_ty elt, expr_ty val, int type)
 {
 	/* generate code for the iterator, then each of the ifs,
 	   and then write to the element */
 
-	comprehension_ty ge;
-	basicblock *start, *anchor, *skip, *if_cleanup, *end;
+	comprehension_ty gen;
+	basicblock *start, *anchor, *skip, *if_cleanup;
 	int i, n;
 
 	start = compiler_new_block(c);
 	skip = compiler_new_block(c);
 	if_cleanup = compiler_new_block(c);
 	anchor = compiler_new_block(c);
-	end = compiler_new_block(c);
 
 	if (start == NULL || skip == NULL || if_cleanup == NULL ||
-	    anchor == NULL || end == NULL)
+	    anchor == NULL)
 		return 0;
 
-	ge = (comprehension_ty)asdl_seq_GET(generators, gen_index);
-	ADDOP_JREL(c, SETUP_LOOP, end);
-	if (!compiler_push_fblock(c, LOOP, start))
-		return 0;
-
+	gen = (comprehension_ty)asdl_seq_GET(generators, gen_index);
+	
 	if (gen_index == 0) {
 		/* Receive outermost iter as an implicit argument */
 		c->u->u_argcount = 1;
@@ -2673,77 +2692,164 @@
 	}
 	else {
 		/* Sub-iter - calculate on the fly */
-		VISIT(c, expr, ge->iter);
+		VISIT(c, expr, gen->iter);
 		ADDOP(c, GET_ITER);
 	}
 	compiler_use_next_block(c, start);
 	ADDOP_JREL(c, FOR_ITER, anchor);
 	NEXT_BLOCK(c);
-	VISIT(c, expr, ge->target);
+	VISIT(c, expr, gen->target);
 
 	/* XXX this needs to be cleaned up...a lot! */
-	n = asdl_seq_LEN(ge->ifs);
+	n = asdl_seq_LEN(gen->ifs);
 	for (i = 0; i < n; i++) {
-		expr_ty e = (expr_ty)asdl_seq_GET(ge->ifs, i);
+		expr_ty e = (expr_ty)asdl_seq_GET(gen->ifs, i);
 		VISIT(c, expr, e);
 		ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup);
 		NEXT_BLOCK(c);
 	}
 
 	if (++gen_index < asdl_seq_LEN(generators))
-		if (!compiler_genexp_generator(c, generators, gen_index, elt))
-			return 0;
+		if (!compiler_comprehension_generator(c, 
+						      generators, gen_index,
+						      elt, val, type))
+		return 0;
 
-	/* only append after the last 'for' generator */
+	/* only append after the last for generator */
 	if (gen_index >= asdl_seq_LEN(generators)) {
-		VISIT(c, expr, elt);
-		ADDOP(c, YIELD_VALUE);
-		ADDOP(c, POP_TOP);
+		/* comprehension specific code */
+		switch (type) {
+		case COMP_GENEXP:
+			VISIT(c, expr, elt);
+			ADDOP(c, YIELD_VALUE);
+			ADDOP(c, POP_TOP);
+			break;
+		case COMP_SETCOMP:
+			VISIT(c, expr, elt);
+			ADDOP_I(c, SET_ADD, gen_index + 1);
+			break;
+		case COMP_DICTCOMP:
+			/* With 'd[k] = v', v is evaluated before k, so we do
+			   the same. */
+			VISIT(c, expr, val);
+			VISIT(c, expr, elt);
+			ADDOP_I(c, MAP_ADD, gen_index + 1);
+			break;
+		default:
+			return 0;
+		}
 
 		compiler_use_next_block(c, skip);
 	}
 	compiler_use_next_block(c, if_cleanup);
 	ADDOP_JABS(c, JUMP_ABSOLUTE, start);
 	compiler_use_next_block(c, anchor);
-	ADDOP(c, POP_BLOCK);
-	compiler_pop_fblock(c, LOOP, start);
-	compiler_use_next_block(c, end);
 
 	return 1;
 }
 
 static int
+compiler_comprehension(struct compiler *c, expr_ty e, int type, identifier name,
+		       asdl_seq *generators, expr_ty elt, expr_ty val)
+{
+	PyCodeObject *co = NULL;
+	expr_ty outermost_iter;
+
+	outermost_iter = ((comprehension_ty)
+			  asdl_seq_GET(generators, 0))->iter;
+
+	if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
+		goto error;
+	
+	if (type != COMP_GENEXP) {
+		int op;
+		switch (type) {
+		case COMP_SETCOMP:
+			op = BUILD_SET;
+			break;
+		case COMP_DICTCOMP:
+			op = BUILD_MAP;
+			break;
+		default:
+			PyErr_Format(PyExc_SystemError,
+				     "unknown comprehension type %d", type);
+			goto error_in_scope;
+		}
+
+		ADDOP_I(c, op, 0);
+	}
+	
+	if (!compiler_comprehension_generator(c, generators, 0, elt,
+					      val, type))
+		goto error_in_scope;
+	
+	if (type != COMP_GENEXP) {
+		ADDOP(c, RETURN_VALUE);
+	}
+
+	co = assemble(c, 1);
+	compiler_exit_scope(c);
+	if (co == NULL)
+		goto error;
+
+	if (!compiler_make_closure(c, co, 0))
+		goto error;
+	Py_DECREF(co);
+
+	VISIT(c, expr, outermost_iter);
+	ADDOP(c, GET_ITER);
+	ADDOP_I(c, CALL_FUNCTION, 1);
+	return 1;
+error_in_scope:
+	compiler_exit_scope(c);
+error:
+	Py_XDECREF(co);
+	return 0;
+}
+
+static int
 compiler_genexp(struct compiler *c, expr_ty e)
 {
 	static identifier name;
-	PyCodeObject *co;
-	expr_ty outermost_iter = ((comprehension_ty)
-				 (asdl_seq_GET(e->v.GeneratorExp.generators,
-					       0)))->iter;
-
 	if (!name) {
 		name = PyString_FromString("<genexpr>");
 		if (!name)
 			return 0;
 	}
+	assert(e->kind == GeneratorExp_kind);
+	return compiler_comprehension(c, e, COMP_GENEXP, name,
+				      e->v.GeneratorExp.generators,
+				      e->v.GeneratorExp.elt, NULL);
+}
 
-	if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
-		return 0;
-	compiler_genexp_generator(c, e->v.GeneratorExp.generators, 0,
-				  e->v.GeneratorExp.elt);
-	co = assemble(c, 1);
-	compiler_exit_scope(c);
-	if (co == NULL)
-		return 0;
+static int
+compiler_setcomp(struct compiler *c, expr_ty e)
+{
+	static identifier name;
+	if (!name) {
+		name = PyString_FromString("<setcomp>");
+		if (!name)
+			return 0;
+	}
+	assert(e->kind == SetComp_kind);
+	return compiler_comprehension(c, e, COMP_SETCOMP, name,
+				      e->v.SetComp.generators,
+				      e->v.SetComp.elt, NULL);
+}
 
-	compiler_make_closure(c, co, 0);
-	Py_DECREF(co);
-
-	VISIT(c, expr, outermost_iter);
-	ADDOP(c, GET_ITER);
-	ADDOP_I(c, CALL_FUNCTION, 1);
-
-	return 1;
+static int
+compiler_dictcomp(struct compiler *c, expr_ty e)
+{
+	static identifier name;
+	if (!name) {
+		name = PyString_FromString("<dictcomp>");
+		if (!name)
+			return 0;
+	}
+	assert(e->kind == DictComp_kind);
+	return compiler_comprehension(c, e, COMP_DICTCOMP, name,
+				      e->v.DictComp.generators,
+				      e->v.DictComp.key, e->v.DictComp.value);
 }
 
 static int
@@ -2902,6 +3008,10 @@
 		break;
 	case ListComp_kind:
 		return compiler_listcomp(c, e);
+	case SetComp_kind:
+		return compiler_setcomp(c, e);
+	case DictComp_kind:
+		return compiler_dictcomp(c, e);
 	case GeneratorExp_kind:
 		return compiler_genexp(c, e);
 	case Yield_kind:
diff --git a/Python/graminit.c b/Python/graminit.c
index 8c8fa38..7cd6ff2 100644
--- a/Python/graminit.c
+++ b/Python/graminit.c
@@ -1550,42 +1550,57 @@
 static arc arcs_73_0[1] = {
 	{28, 1},
 };
-static arc arcs_73_1[3] = {
+static arc arcs_73_1[4] = {
 	{23, 2},
-	{29, 3},
+	{157, 3},
+	{29, 4},
 	{0, 1},
 };
 static arc arcs_73_2[1] = {
-	{28, 4},
-};
-static arc arcs_73_3[2] = {
 	{28, 5},
+};
+static arc arcs_73_3[1] = {
 	{0, 3},
 };
 static arc arcs_73_4[2] = {
-	{29, 6},
+	{28, 6},
 	{0, 4},
 };
-static arc arcs_73_5[2] = {
-	{29, 3},
+static arc arcs_73_5[3] = {
+	{157, 3},
+	{29, 7},
 	{0, 5},
 };
 static arc arcs_73_6[2] = {
-	{28, 7},
+	{29, 4},
 	{0, 6},
 };
-static arc arcs_73_7[1] = {
-	{23, 2},
+static arc arcs_73_7[2] = {
+	{28, 8},
+	{0, 7},
 };
-static state states_73[8] = {
+static arc arcs_73_8[1] = {
+	{23, 9},
+};
+static arc arcs_73_9[1] = {
+	{28, 10},
+};
+static arc arcs_73_10[2] = {
+	{29, 7},
+	{0, 10},
+};
+static state states_73[11] = {
 	{1, arcs_73_0},
-	{3, arcs_73_1},
+	{4, arcs_73_1},
 	{1, arcs_73_2},
-	{2, arcs_73_3},
+	{1, arcs_73_3},
 	{2, arcs_73_4},
-	{2, arcs_73_5},
+	{3, arcs_73_5},
 	{2, arcs_73_6},
-	{1, arcs_73_7},
+	{2, arcs_73_7},
+	{1, arcs_73_8},
+	{1, arcs_73_9},
+	{2, arcs_73_10},
 };
 static arc arcs_74_0[1] = {
 	{162, 1},
@@ -1964,7 +1979,7 @@
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\044\015\000\000"},
 	{319, "listmaker", 0, 5, states_63,
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
-	{320, "testlist_gexp", 0, 5, states_64,
+	{320, "testlist_comp", 0, 5, states_64,
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
 	{321, "lambdef", 0, 5, states_65,
 	 "\000\000\000\000\000\000\000\000\000\000\000\000\000\040\000\000\000\000\000\000\000\000"},
@@ -1982,7 +1997,7 @@
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
 	{328, "dictmaker", 0, 5, states_72,
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
-	{329, "dictorsetmaker", 0, 8, states_73,
+	{329, "dictorsetmaker", 0, 11, states_73,
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
 	{330, "classdef", 0, 8, states_74,
 	 "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\004\000"},
@@ -1996,11 +2011,11 @@
 	 "\000\000\000\000\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000\000\000\000"},
 	{335, "list_if", 0, 4, states_79,
 	 "\000\000\000\000\000\000\000\000\000\000\000\020\000\000\000\000\000\000\000\000\000\000"},
-	{336, "gen_iter", 0, 2, states_80,
+	{336, "comp_iter", 0, 2, states_80,
 	 "\000\000\000\000\000\000\000\000\000\000\000\020\001\000\000\000\000\000\000\000\000\000"},
-	{337, "gen_for", 0, 6, states_81,
+	{337, "comp_for", 0, 6, states_81,
 	 "\000\000\000\000\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000\000\000\000"},
-	{338, "gen_if", 0, 4, states_82,
+	{338, "comp_if", 0, 4, states_82,
 	 "\000\000\000\000\000\000\000\000\000\000\000\020\000\000\000\000\000\000\000\000\000\000"},
 	{339, "testlist1", 0, 2, states_83,
 	 "\000\040\040\000\000\000\000\000\000\000\000\000\000\040\010\000\200\041\044\015\000\000"},
diff --git a/Python/import.c b/Python/import.c
index 3df70a8..c25c4f0 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -76,9 +76,10 @@
 			    introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
        Python 2.7a0  62191 (introduce SETUP_WITH)
        Python 2.7a0  62201 (introduce BUILD_SET)
+       Python 2.7a0  62211 (introduce MAP_ADD and SET_ADD)
 .
 */
-#define MAGIC (62201 | ((long)'\r'<<16) | ((long)'\n'<<24))
+#define MAGIC (62211 | ((long)'\r'<<16) | ((long)'\n'<<24))
 
 /* Magic word as global; note that _PyImport_Init() can change the
    value of this global to accommodate for alterations of how the
diff --git a/Python/symtable.c b/Python/symtable.c
index 5e735cc..0c463a2 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -166,6 +166,8 @@
 static int symtable_visit_stmt(struct symtable *st, stmt_ty s);
 static int symtable_visit_expr(struct symtable *st, expr_ty s);
 static int symtable_visit_genexp(struct symtable *st, expr_ty s);
+static int symtable_visit_setcomp(struct symtable *st, expr_ty e);
+static int symtable_visit_dictcomp(struct symtable *st, expr_ty e);
 static int symtable_visit_arguments(struct symtable *st, arguments_ty);
 static int symtable_visit_excepthandler(struct symtable *st, excepthandler_ty);
 static int symtable_visit_alias(struct symtable *st, alias_ty);
@@ -177,7 +179,8 @@
 static int symtable_implicit_arg(struct symtable *st, int pos);
 
 
-static identifier top = NULL, lambda = NULL, genexpr = NULL;
+static identifier top = NULL, lambda = NULL, genexpr = NULL, setcomp = NULL,
+	dictcomp = NULL;
 
 #define GET_IDENTIFIER(VAR) \
 	((VAR) ? (VAR) : ((VAR) = PyString_InternFromString(# VAR)))
@@ -1222,6 +1225,14 @@
 		if (!symtable_visit_genexp(st, e))
 			return 0;
 		break;
+	case SetComp_kind:
+		if (!symtable_visit_setcomp(st, e))
+			return 0;
+		break;
+	case DictComp_kind:
+		if (!symtable_visit_dictcomp(st, e))
+			return 0;
+		break;
         case Yield_kind:
 		if (e->v.Yield.value)
 			VISIT(st, expr, e->v.Yield.value);
@@ -1462,28 +1473,81 @@
 	return 1;
 }
 
-static int 
-symtable_visit_genexp(struct symtable *st, expr_ty e)
+static int
+symtable_new_tmpname(struct symtable *st)
 {
+	char tmpname[256];
+	identifier tmp;
+
+	PyOS_snprintf(tmpname, sizeof(tmpname), "_[%d]",
+		      ++st->st_cur->ste_tmpname);
+	tmp = PyString_InternFromString(tmpname);
+	if (!tmp)
+		return 0;
+	if (!symtable_add_def(st, tmp, DEF_LOCAL))
+		return 0;
+	Py_DECREF(tmp);
+	return 1;
+}
+
+static int 
+symtable_handle_comprehension(struct symtable *st, expr_ty e,
+                              identifier scope_name, asdl_seq *generators,
+                              expr_ty elt, expr_ty value)
+{
+	int is_generator = (e->kind == GeneratorExp_kind);
+	int needs_tmp = !is_generator;
 	comprehension_ty outermost = ((comprehension_ty)
-			 (asdl_seq_GET(e->v.GeneratorExp.generators, 0)));
+                                        asdl_seq_GET(generators, 0));
 	/* Outermost iterator is evaluated in current scope */
 	VISIT(st, expr, outermost->iter);
-	/* Create generator scope for the rest */
-	if (!GET_IDENTIFIER(genexpr) ||
-	    !symtable_enter_block(st, genexpr, FunctionBlock, (void *)e, e->lineno)) {
+	/* Create comprehension scope for the rest */
+	if (!scope_name ||
+	    !symtable_enter_block(st, scope_name, FunctionBlock, (void *)e, 0)) {
 		return 0;
 	}
-	st->st_cur->ste_generator = 1;
+	st->st_cur->ste_generator = is_generator;
 	/* Outermost iter is received as an argument */
 	if (!symtable_implicit_arg(st, 0)) {
 		symtable_exit_block(st, (void *)e);
 		return 0;
 	}
+	/* Allocate temporary name if needed */
+	if (needs_tmp && !symtable_new_tmpname(st)) {
+		symtable_exit_block(st, (void *)e);
+		return 0;
+	}
 	VISIT_IN_BLOCK(st, expr, outermost->target, (void*)e);
 	VISIT_SEQ_IN_BLOCK(st, expr, outermost->ifs, (void*)e);
 	VISIT_SEQ_TAIL_IN_BLOCK(st, comprehension,
-				e->v.GeneratorExp.generators, 1, (void*)e);
-	VISIT_IN_BLOCK(st, expr, e->v.GeneratorExp.elt, (void*)e);
+				generators, 1, (void*)e);
+	if (value)
+		VISIT_IN_BLOCK(st, expr, value, (void*)e);
+	VISIT_IN_BLOCK(st, expr, elt, (void*)e);
 	return symtable_exit_block(st, (void *)e);
 }
+
+static int 
+symtable_visit_genexp(struct symtable *st, expr_ty e)
+{
+	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(genexpr),
+                                             e->v.GeneratorExp.generators,
+                                             e->v.GeneratorExp.elt, NULL);
+}
+
+static int
+symtable_visit_setcomp(struct symtable *st, expr_ty e)
+{
+	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(setcomp),
+					     e->v.SetComp.generators,
+					     e->v.SetComp.elt, NULL);
+}
+
+static int
+symtable_visit_dictcomp(struct symtable *st, expr_ty e)
+{
+	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(dictcomp),
+					     e->v.DictComp.generators,
+					     e->v.DictComp.key,
+					     e->v.DictComp.value);
+}