python-3.6.zip added from Github

README.cosmo contains the necessary links.

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

@@ -0,0 +1,25 @@
+"""Fix "for x in f.xreadlines()" -> "for x in f".
+
+This fixer will also convert g(f.xreadlines) into g(f.__iter__)."""
+# Author: Collin Winter
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+
+class FixXreadlines(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+    power< call=any+ trailer< '.' 'xreadlines' > trailer< '(' ')' > >
+    |
+    power< any+ trailer< '.' no_call='xreadlines' > >
+    """
+
+    def transform(self, node, results):
+        no_call = results.get("no_call")
+
+        if no_call:
+            no_call.replace(Name("__iter__", prefix=no_call.prefix))
+        else:
+            node.replace([x.clone() for x in results["call"]])