Use singleton

Singleton.py

@@ -0,0 +1,35 @@
+"""app.coordinates.py"""
+
+
+class Coordinates:
+    __instance = None
+    """
+    A position on earth using decimal coordinates (latitude and longitude).
+    """
+
+    def __init__(self, latitude, longitude):
+        if Coordinates.__instance is not None:
+            raise Exception("I have already got an latitude and longitude")
+        else:
+            self.latitude = latitude
+            self.longitude = longitude
+
+    @staticmethod
+    def get_instance():
+        if Coordinates.__instance is None:
+            Coordinates(0, 0)
+        return Coordinates.__instance
+
+
+
+    def serialize(self):
+        """
+        Serializes the coordinates into a dict.
+
+        :returns: The serialized coordinates.
+        :rtype: dict
+        """
+        return {"latitude": self.latitude, "longitude": self.longitude}
+
+    def __str__(self):
+        return "lat: %s, long: %s" % (self.latitude, self.longitude)