python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/lib2to3/fixes/fix_nonzero.py

@@ -0,0 +1,21 @@
+"""Fixer for __nonzero__ -> __bool__ methods."""
+# Author: Collin Winter
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+class FixNonzero(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+    classdef< 'class' any+ ':'
+              suite< any*
+                     funcdef< 'def' name='__nonzero__'
+                              parameters< '(' NAME ')' > any+ >
+                     any* > >
+    """
+
+    def transform(self, node, results):
+        name = results["name"]
+        new = Name("__bool__", prefix=name.prefix)
+        name.replace(new)