Extract vector helpers to a file

main.py

@@ -1,35 +1,14 @@
-import math
+from typing import Any, Iterable, List, Optional, Set, Tuple
 
 from load import load_words
-from word import Word, Vector
+import math
 from operator import itemgetter
-from typing import Any, Iterable, List, Optional, Set, Tuple
-
-def vector_len(v: Vector) -> float:
-    return math.sqrt(sum([x*x for x in v]))
-
-def dot_product(v1: Vector, v2: Vector) -> float:
-    assert len(v1) == len(v2)
-    return sum([x*y for (x,y) in zip(v1, v2)])
-
-def add_vectors(v1: Vector, v2: Vector) -> Vector:
-    assert len(v1) == len(v2)
-    return [x + y for (x,y) in zip(v1, v2)]
-
-def sub_vectors(v1: Vector, v2: Vector) -> Vector:
-    assert len(v1) == len(v2)
-    return [x - y for (x,y) in zip(v1, v2)]
-
-def cosine_similarity(v1: Vector, v2: Vector) -> float:
-    """
-    Returns the cosine of the angle between the two vectors.
-    Results range from -1 (very different) to 1 (very similar).
-    """
-    return dot_product(v1, v2) / float(vector_len(v1) * vector_len(v2))
+import vectors as v
+from word import Word, Vector
 
 def most_similar(base_vector: Vector, words: List[Word]) -> List[Tuple[float, Word]]:
     """Finds n words with smallest cosine similarity to a given word"""
-    words_with_distance = [(cosine_similarity(base_vector, w.vector), w) for w in words]
+    words_with_distance = [(v.cosine_similarity(base_vector, w.vector), w) for w in words]
     # We want cosine similarity to be as large as possible (close to 1)
     sorted_by_distance = sorted(words_with_distance, key=lambda t: t[0], reverse=True)
     return sorted_by_distance
@@ -64,8 +43,8 @@ def closest_analogies(
     word_right2 = find_word(right2, words)
     if (not word_left1) or (not word_left2) or (not word_right2):
         return []
-    vector = add_vectors(
-        sub_vectors(word_left1.vector, word_left2.vector),
+    vector = v.add(
+        v.sub(word_left1.vector, word_left2.vector),
         word_right2.vector)
     closest = most_similar(vector, words)[:10]
     def is_redundant(word: str) -> bool:

word.py

@@ -1,6 +1,5 @@
 from typing import List
-
-Vector = List[float]
+from vectors import Vector
 
 class Word:
     """A single word (one line of the input file)"""