Added Dictionary class

dictionary.py

@@ -0,0 +1,46 @@
+import spellchecker
+import pathlib
+import concurrent
+from concurrent.futures import ThreadPoolExecutor
+EXECUTOR = ThreadPoolExecutor()
+DEFAULT = spellchecker.WordFrequency()
+ALTERNATE = spellchecker.WordFrequency()
+
+
+package_root = pathlib.Path(spellchecker.__file__) / '..'
+english = package_root / 'resources' / 'en.json.gz'
+
+extra_words = pathlib.Path(__file__, '..', 'extra_words.txt')
+
+
+def do_operation(obj, bound_method, *args, **kwargs):
+    bound_method(*args, **kwargs)
+    import time
+    time.sleep(60)
+    return obj
+
+
+default_load_future = EXECUTOR.submit(
+    do_operation, DEFAULT, DEFAULT.load_dictionary, english)
+alternate_load_future = EXECUTOR.submit(
+    do_operation, ALTERNATE, ALTERNATE.load_text_file, english)
+
+
+class Dictionary:
+    def __init__(self, loader_future: concurrent.futures._base.Future):
+        self.future = loader_future
+        self._word_frequency = None
+
+    @property
+    def word_frequency(self) -> spellchecker.WordFrequency:
+        if self._word_frequency is None:
+            self._word_frequency = self.future.result()
+        return self._word_frequency
+
+    def filter(self, wordlist):
+        """Finds words that are in the dictionary"""
+        return set(filter(wordlist, lambda word: word in self.word_frequency))
+
+
+DEFAULT = Dictionary(default_load_future)
+ALTERNATE = Dictionary(alternate_load_future)