Merge pull request #148 from kayjan/abstract-newick

Abstract newick

Author: kayjan

tests/test_constants.py

@@ -151,6 +151,7 @@ class Constants:
     ERROR_NODE_MERMAID_INVALID_ARGUMENT = (
         "Invalid input, check `{parameter}` should be one of "
     )
+    ERROR_NODE_NEWICK_ATTR_INVALID = "Length attribute does not exist for node "
 
     # tree/helper
     ERROR_NODE_PRUNE_ARGUMENT = (

tests/tree/test_export.py

@@ -1397,9 +1397,7 @@ def test_tree_to_newick_length(tree_node):
     def test_tree_to_newick_length_invalid_error(tree_node):
         with pytest.raises(ValueError) as exc_info:
             tree_to_newick(tree_node, length_attr="age2")
-        assert str(exc_info.value).startswith(
-            "Length attribute does not exist for node "
-        )
+        assert str(exc_info.value).startswith(Constants.ERROR_NODE_NEWICK_ATTR_INVALID)
 
     @staticmethod
     def test_tree_to_newick_length_sep(tree_node):