added option to get variable from ID instead of name or cf_standard_name

src/toargridding/static_metadata.py

@@ -112,6 +112,26 @@ class TOARVariable:
                 return var
         msg = f"TOAR Database contains no variable {name}"
         raise ValueError(msg)
+    
+    @classmethod
+    def get_from_id(cls, id : int) -> "TOARVariable":
+        """searches the known variables for the given id
+
+        Parameters:
+        ----------
+        id:
+            id of the variable according to the TOAR database config
+
+        return:
+            provides direct access to the meta data of the selected variable
+        """
+        if id == None:
+            raise ValueError("No id provided for variable.")
+        for var in cls.vars:
+            if var.id == id:
+                return var
+        msg = f"TOAR Database contains no variable with id {id}"
+        raise ValueError(msg)
 
     @property
     def toar_id(self):