Use not results

Author: xhochy

pandas/core/arrays/boolean.py

@@ -126,7 +126,7 @@ def __from_arrow__(
             bool_arr = BooleanArray._from_sequence(np.array(arr))
             results.append(bool_arr)
 
-        if len(results) == 0:
+        if not results:
             return BooleanArray(
                 np.array([], dtype=np.bool_), np.array([], dtype=np.bool_)
             )

pandas/core/arrays/numeric.py

@@ -66,7 +66,7 @@ def __from_arrow__(
             num_arr = array_class(data.copy(), ~mask, copy=False)
             results.append(num_arr)
 
-        if len(results) == 0:
+        if not results:
             return array_class(
                 np.array([], dtype=self.numpy_dtype), np.array([], dtype=np.bool_)
             )

pandas/core/arrays/string_.py

@@ -118,7 +118,7 @@ def __from_arrow__(
             str_arr = StringArray._from_sequence(np.array(arr))
             results.append(str_arr)
 
-        if len(results) > 0:
+        if results:
             return StringArray._concat_same_type(results)
         else:
             return StringArray(np.array([], dtype="object"))