Word lists can be combined using the plus operator (#15)

blacksquare/word_list.py

@@ -5,9 +5,7 @@
 from collections import defaultdict
 from functools import lru_cache
 from pathlib import Path
-from typing import (TYPE_CHECKING, Callable, Dict, List, NamedTuple, Optional,
-                    Union)
-from xml.dom import INVALID_ACCESS_ERR
+from typing import TYPE_CHECKING, Callable, Dict, List, NamedTuple, Optional, Union
 
 import numpy as np
 import pandas as pd
@@ -237,6 +235,11 @@ def __next__(self):
         else:
             raise StopIteration
 
+    def __add__(self, other):
+        return WordList(
+            {w: s for w, s in zip(self.words + other.words, self.scores + other.scores)}
+        )
+
 
 class MatchWordList(WordList):
     """An object representing a WordList matching an open word. This class should not be

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = blacksquare
-version = 0.3.1
+version = 0.4.0
 author = Patrick Maher
 author_email = [email protected]
 description = "A package for creating crossword puzzles"

tests/test_word_list.py

@@ -49,6 +49,13 @@ def test_get_score(self, word_list):
         assert word_list.get_score("BBB") == 0.1
         assert word_list.get_score("XYZ") is None
 
+    def test_add_word_list(self):
+        word_list_1 = {"ZZZ": 0.1, "AAA": 1.0}
+        word_list_2 = {"ABC": 0.9, "XYZ": 1.0}
+        new_word_list = WordList(word_list_1) + WordList(word_list_2)
+        assert new_word_list.words == ["AAA", "XYZ", "ABC", "ZZZ"]
+        assert new_word_list.scores == [1.0, 1.0, 0.9, 0.1]
+
 
 class TestMatchWordList:
     @pytest.fixture