Added comments [skip ci]

Author: ankane

pgvector/halfvec.py

@@ -25,6 +25,7 @@ def __init__(self, value: list[float] | np.ndarray[tuple[int], np.dtype[np.float
             if value.dtype != np.float16:
                 value = np.asarray(value, dtype=np.float16)
 
+            # tobytes() important for performance
             self._value = array.array('H', value.tobytes())
         else:
             raise ValueError('expected list or ndarray')

pgvector/vector.py

@@ -24,6 +24,7 @@ def __init__(self, value: list[float] | np.ndarray[tuple[int], np.dtype[np.float
             if value.dtype != np.float32:
                 value = np.asarray(value, dtype=np.float32)
 
+            # tobytes() important for performance
             self._value = array.array('f', value.tobytes())
         else:
             raise ValueError('expected list or ndarray')