Add support for variable annotations

CHANGES

@@ -11,4 +11,5 @@
 0.4.1   -- Added missing SourceGenerator.visit_arguments()
 0.5     -- Added support for Python 3.5 infix matrix
            multiplication
-0.6     -- Added support for Python 3.6 f-strings and async comprehensions.
+0.6     -- Added support for Python 3.6 f-strings, async comprehensions, and
+           variable annotations.

astor/code_gen.py

@@ -247,6 +247,17 @@ class SourceGenerator(ExplicitNodeVisitor):
         self.statement(node, node.target, get_op_symbol(node.op, ' %s= '),
                        node.value)
 
+    def visit_AnnAssign(self, node):
+        set_precedence(node, node.value, node.target)
+        self.newline(node)
+        if not node.simple and isinstance(node.target, ast.Name):
+            self.write('(', node.target, ')')
+        else:
+            self.write(node.target)
+        self.write(': ', node.annotation)
+        if node.value is not None:
+            self.write(' = ', node.value)
+
     def visit_ImportFrom(self, node):
         self.statement(node, 'from ', node.level * '.',
                        node.module or '', ' import ')

astor/op_util.py

@@ -17,6 +17,7 @@ op_data = """
     GeneratorExp                1
 
           Assign                1
+       AnnAssign                1
        AugAssign                0
             Expr                0
            Yield                1

tests/test_code_gen.py

@@ -373,5 +373,13 @@ class CodegenTestCase(unittest.TestCase):
         """
         self.assertAstSourceEqualIfAtLeastVersion(source, (3, 6))
 
+    def test_annassign(self):
+        source = """
+            a: int
+            (b): Tuple[int, str, ...]
+            c.d[e].f: Any
+        """
+        self.assertAstEqualIfAtLeastVersion(source, (3, 6))
+
 if __name__ == '__main__':
     unittest.main()