add get_setupcodebegin to python bindings, test the function

python/src/deltachat/message.py

@@ -101,6 +101,10 @@ class Message(object):
         """ return True if this message is a setup message. """
         return lib.dc_msg_is_setupmessage(self._dc_msg)
 
+    def get_setupcodebegin(self):
+        """ return the first characters of a setup code in a setup message. """
+        return from_dc_charpointer(lib.dc_msg_get_setupcodebegin(self._dc_msg))
+
     def is_encrypted(self):
         """ return True if this message was encrypted. """
         return bool(lib.dc_msg_get_showpadlock(self._dc_msg))

python/tests/test_account.py

@@ -537,6 +537,7 @@ class TestOnlineAccount:
         ev = ac2._evlogger.get_matching("DC_EVENT_INCOMING_MSG|DC_EVENT_MSGS_CHANGED")
         msg = ac2.get_message_by_id(ev[2])
         assert msg.is_setup_message()
+        assert msg.get_setupcodebegin() == setup_code[:2]
         # first try a bad setup code
         with pytest.raises(ValueError):
             msg.continue_key_transfer(str(reversed(setup_code)))