Add PyCon talk link to README (#844)

[etc/vim.git] / blib2to3 / pgen2 / grammar.py

diff --git a/blib2to3/pgen2/grammar.py b/blib2to3/pgen2/grammar.py
index c00cb2248d5676092c82d9da3f67d9b2f54f67ad..3ccf38ff9d80acc344ae6acbfb12433a9f9542bc 100644 (file)
--- a/blib2to3/pgen2/grammar.py
+++ b/blib2to3/pgen2/grammar.py
@@ -13,8 +13,9 @@ fallback token code OP, but the parser needs the actual token code.
 """
 
 # Python imports
-import collections
+import os
 import pickle
+import tempfile
 
 # Local imports
 from . import token
@@ -87,8 +88,9 @@ class Grammar(object):
 
     def dump(self, filename):
         """Dump the grammar tables to a pickle file."""
-        with open(filename, "wb") as f:
+        with tempfile.NamedTemporaryFile(dir=os.path.dirname(filename), delete=False) as f:
             pickle.dump(self.__dict__, f, pickle.HIGHEST_PROTOCOL)
+        os.replace(f.name, filename)
 
     def load(self, filename):
         """Load the grammar tables from a pickle file."""