Fix some clippy lints

src/class/sequence.rs

@@ -146,7 +146,7 @@ where
     T: PySequenceProtocol<'p>,
 {
     fn tp_as_sequence() -> Option<ffi::PySequenceMethods> {
-        return Some(ffi::PySequenceMethods {
+        Some(ffi::PySequenceMethods {
             sq_length: Self::sq_length(),
             sq_concat: Self::sq_concat(),
             sq_repeat: Self::sq_repeat(),
@@ -157,7 +157,7 @@ where
             sq_contains: Self::sq_contains(),
             sq_inplace_concat: Self::sq_inplace_concat(),
             sq_inplace_repeat: Self::sq_inplace_repeat(),
-        });
+        })
     }
 }
 

src/types/list.rs

@@ -20,10 +20,7 @@ pyobject_native_type!(PyList, ffi::PyList_Type, ffi::PyList_Check);
 
 impl PyList {
     /// Construct a new list with the given elements.
-    pub fn new<'p, T, U>(
-        py: Python<'p>,
-        elements: impl IntoIterator<Item = T, IntoIter = U>,
-    ) -> &'p PyList
+    pub fn new<T, U>(py: Python<'_>, elements: impl IntoIterator<Item = T, IntoIter = U>) -> &PyList
     where
         T: ToPyObject,
         U: ExactSizeIterator<Item = T>,

src/types/sequence.rs

@@ -27,6 +27,11 @@ impl PySequence {
         }
     }
 
+    #[inline]
+    pub fn is_empty(&self) -> PyResult<bool> {
+        self.len().map(|l| l == 0)
+    }
+
     /// Return the concatenation of o1 and o2. Equivalent to python `o1 + o2`
     #[inline]
     pub fn concat(&self, other: &PySequence) -> PyResult<&PySequence> {
@@ -656,4 +661,17 @@ mod test {
         let seq_from = unsafe { <PySequence as PyTryFrom>::try_from_unchecked(type_ptr) };
         assert!(seq_from.list().is_ok());
     }
+
+    #[test]
+    fn test_is_empty() {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
+        let list = vec![1].to_object(py);
+        let seq = list.cast_as::<PySequence>(py).unwrap();
+        assert_eq!(seq.is_empty().unwrap(), false);
+        let vec: Vec<u32> = Vec::new();
+        let empty_list = vec.to_object(py);
+        let empty_seq = empty_list.cast_as::<PySequence>(py).unwrap();
+        assert_eq!(empty_seq.is_empty().unwrap(), true);
+    }
 }