From 485c078f4f37d5737ea624021acd8937a7145d09 Mon Sep 17 00:00:00 2001
From: David Bieber <dbieber@google.com>
Date: Thu, 6 Sep 2018 00:10:10 -0700
Subject: [PATCH] Allow user to specify version_info rather than assuming AST
 version matches the current Python version. This is useful if the user is
 using e.g. gast to get a different AST version from the Python version they
 are using.

---
 lib/astunparse/unparser.py | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/lib/astunparse/unparser.py b/lib/astunparse/unparser.py
index 767412c..e4df04b 100644
--- a/lib/astunparse/unparser.py
+++ b/lib/astunparse/unparser.py
@@ -24,14 +24,15 @@ def interleave(inter, f, seq):
             inter()
             f(x)
 
-class Unparser:
+class Unparser(object):
     """Methods in this class recursively traverse an AST and
     output source code for the abstract syntax; original formatting
     is disregarded. """
 
-    def __init__(self, tree, file=sys.stdout):
+    def __init__(self, tree, file=sys.stdout, version_info=None):
         """Unparser(tree, file=sys.stdout) -> None.
          Print the source for tree to file."""
+        self.version_info = version_info or sys.version_info
         self.f = file
         self.future_imports = []
         self._indent = 0
@@ -207,7 +208,7 @@ def _YieldFrom(self, t):
 
     def _Raise(self, t):
         self.fill("raise")
-        if six.PY3:
+        if self.version_info[0] == 3:
             if not t.exc:
                 assert not t.cause
                 return
@@ -281,7 +282,7 @@ def _ExceptHandler(self, t):
             self.dispatch(t.type)
         if t.name:
             self.write(" as ")
-            if six.PY3:
+            if isinstance(t.name, six.string_types):
                 self.write(t.name)
             else:
                 self.dispatch(t.name)
@@ -295,7 +296,7 @@ def _ClassDef(self, t):
             self.fill("@")
             self.dispatch(deco)
         self.fill("class "+t.name)
-        if six.PY3:
+        if self.version_info[0] == 3:
             self.write("(")
             comma = False
             for e in t.bases:
@@ -306,7 +307,7 @@ def _ClassDef(self, t):
                 if comma: self.write(", ")
                 else: comma = True
                 self.dispatch(e)
-            if sys.version_info[:2] < (3, 5):
+            if self.version_info[:2] < (3, 5):
                 if t.starargs:
                     if comma: self.write(", ")
                     else: comma = True
@@ -427,7 +428,7 @@ def _Bytes(self, t):
         self.write(repr(t.s))
 
     def _Str(self, tree):
-        if six.PY3:
+        if self.version_info[0] == 3:
             self.write(repr(tree.s))
         else:
             # if from __future__ import unicode_literals is in effect,
@@ -501,7 +502,7 @@ def _Repr(self, t):
 
     def _Num(self, t):
         repr_n = repr(t.n)
-        if six.PY3:
+        if self.version_info[0] == 3:
             self.write(repr_n.replace("inf", INFSTR))
         else:
             # Parenthesize negative numbers, to avoid turning (-1)**2 into -1**2.
@@ -608,7 +609,7 @@ def _UnaryOp(self, t):
         self.write("(")
         self.write(self.unop[t.op.__class__.__name__])
         self.write(" ")
-        if six.PY2 and isinstance(t.op, ast.USub) and isinstance(t.operand, ast.Num):
+        if self.version_info[0] == 2 and isinstance(t.op, ast.USub) and isinstance(t.operand, ast.Num):
             # If we're applying unary minus to a number, parenthesize the number.
             # This is necessary: -2147483648 is different from -(2147483648) on
             # a 32-bit machine (the first is an int, the second a long), and
@@ -671,7 +672,7 @@ def _Call(self, t):
             if comma: self.write(", ")
             else: comma = True
             self.dispatch(e)
-        if sys.version_info[:2] < (3, 5):
+        if self.version_info[:2] < (3, 5):
             if t.starargs:
                 if comma: self.write(", ")
                 else: comma = True
@@ -770,6 +771,11 @@ def _arguments(self, t):
                 if t.kwarg.annotation:
                     self.write(": ")
                     self.dispatch(t.kwarg.annotation)
+            elif hasattr(t.kwarg, 'id'):
+                self.write("**"+t.kwarg.id)
+                if t.kwarg.annotation:
+                    self.write(": ")
+                    self.dispatch(t.kwarg.annotation)
             else:
                 self.write("**"+t.kwarg)
                 if getattr(t, 'kwargannotation', None):