bpo-43651: Fix EncodingWarning in lib2to3/pgen2/pgen.py (GH-25127)

diff --git a/Lib/lib2to3/pgen2/pgen.py b/Lib/lib2to3/pgen2/pgen.py
index b0cbd16c4dad4fbf8b7afc8c776786dc7ad997ec..7abd5cef1c36bb90f340fa6d308672537292ef1f 100644 (file)
--- a/Lib/lib2to3/pgen2/pgen.py
+++ b/Lib/lib2to3/pgen2/pgen.py
@@ -12,7 +12,7 @@ class ParserGenerator(object):
     def __init__(self, filename, stream=None):
         close_stream = None
         if stream is None:
-            stream = open(filename)
+            stream = open(filename, encoding="utf-8")
             close_stream = stream.close
         self.filename = filename
         self.stream = stream