fix import not in feature cfg

src/attribute.rs

@@ -26,8 +26,7 @@ use serde::{de::Visitor, Deserialize, Serialize};
 use std::{error::Error, fmt, str::FromStr};
 
 #[cfg(feature = "python")]
-use pyo3::pyclass;
-use pyo3::pymethods;
+use pyo3::{pyclass, pymethods};
 
 /// Represents an attribute with various properties and options.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]