python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Tools/freeze/bkfile.py

@@ -0,0 +1,26 @@
+from builtins import open as _orig_open
+
+def open(file, mode='r', bufsize=-1):
+    if 'w' not in mode:
+        return _orig_open(file, mode, bufsize)
+    import os
+    backup = file + '~'
+    try:
+        os.unlink(backup)
+    except OSError:
+        pass
+    try:
+        os.rename(file, backup)
+    except OSError:
+        return _orig_open(file, mode, bufsize)
+    f = _orig_open(file, mode, bufsize)
+    _orig_close = f.close
+    def close():
+        _orig_close()
+        import filecmp
+        if filecmp.cmp(backup, file, shallow=False):
+            import os
+            os.unlink(file)
+            os.rename(backup, file)
+    f.close = close
+    return f