feat: Vector subtraction

quantio/vector.py

@@ -33,6 +33,11 @@ def __add__(self, other: Vector[T] | np.ndarray) -> Vector[T]:
         other_elements = other._elements if isinstance(other, Vector) else np.array(other)
         return Vector[T](self._elements + other_elements)
 
+    def __sub__(self, other: Vector[T] | np.ndarray) -> Vector[T]:
+        """Subtract another vector from this one."""
+        other_elements = other._elements if isinstance(other, Vector) else np.array(other)
+        return Vector[T](self._elements - other_elements)
+
     def __eq__(self, other: object) -> bool:
         """Assess if this object is the same as another."""
         if not isinstance(other, Vector):

test/test_vector.py

@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from quantio import Vector, Length, CanNotAddTypesError
+from quantio import Vector, Length, CanNotAddTypesError, CanNotSubtractTypesError
 
 
 def test_init():
@@ -43,5 +43,21 @@ def test_addition__wrong_type():
         vec1 + vec2
 
 
+def test_subtract():
+    vec1: Vector[Length] = Vector([Length(meters=1), Length(meters=2)])
+    vec2: Vector[Length] = Vector([Length(meters=3), Length(meters=3)])
+
+    actual = vec2 - vec1
+    assert actual == Vector([Length(meters=2), Length(meters=1)])
+
+
+def test_subtract__wrong_type():
+    vec1: Vector[Length] = Vector([Length(meters=1), Length(meters=2)])
+    vec2: Vector[float] = Vector([3, 4])
+
+    with pytest.raises(CanNotSubtractTypesError):
+        vec1 - vec2
+
+
 if __name__ == "__main__":
     pytest.main([__file__, "-v"])