nbytes attribute (#92)

arro3-core/python/arro3/core/_core.pyi

@@ -56,6 +56,8 @@ class Array:
             target_type: Type to cast array to.
         """
 
+    @property
+    def nbytes(self) -> int: ...
     def slice(self, offset: int = 0, length: int | None = None) -> Array:
         """Compute zero-copy slice of this array.
 
@@ -126,6 +128,8 @@ class ChunkedArray:
     def equals(self, other: ArrowStreamExportable) -> bool: ...
     def length(self) -> int: ...
     @property
+    def nbytes(self) -> int: ...
+    @property
     def null_count(self) -> int: ...
     @property
     def num_chunks(self) -> int: ...
@@ -696,6 +700,8 @@ class RecordBatch:
             _description_
         """
     @property
+    def nbytes(self) -> int: ...
+    @property
     def num_columns(self) -> int:
         """Number of columns."""
     @property
@@ -1122,6 +1128,8 @@ class Table:
             _description_
         """
     @property
+    def nbytes(self) -> int: ...
+    @property
     def num_columns(self) -> int:
         """Number of columns in this table."""
     @property

pyo3-arrow/src/array.rs

@@ -282,6 +282,11 @@ impl PyArray {
         Ok(PyArray::new(new_array, new_field.into()).to_arro3(py)?)
     }
 
+    #[getter]
+    fn nbytes(&self) -> usize {
+        self.array.get_array_memory_size()
+    }
+
     #[pyo3(signature = (offset=0, length=None))]
     pub fn slice(&self, py: Python, offset: usize, length: Option<usize>) -> PyResult<PyObject> {
         let length = length.unwrap_or_else(|| self.array.len() - offset);

pyo3-arrow/src/chunked.rs

@@ -366,6 +366,13 @@ impl PyChunkedArray {
         self.len()
     }
 
+    #[getter]
+    fn nbytes(&self) -> usize {
+        self.chunks
+            .iter()
+            .fold(0, |acc, batch| acc + batch.get_array_memory_size())
+    }
+
     #[getter]
     pub fn null_count(&self) -> usize {
         self.chunks

pyo3-arrow/src/record_batch.rs

@@ -327,6 +327,11 @@ impl PyRecordBatch {
         PyField::new(field.clone().into()).to_arro3(py)
     }
 
+    #[getter]
+    fn nbytes(&self) -> usize {
+        self.0.get_array_memory_size()
+    }
+
     /// Number of columns in this RecordBatch.
     #[getter]
     pub fn num_columns(&self) -> usize {

pyo3-arrow/src/table.rs

@@ -376,6 +376,13 @@ impl PyTable {
         Ok(PyField::new(field.clone().into()).to_arro3(py)?)
     }
 
+    #[getter]
+    fn nbytes(&self) -> usize {
+        self.batches
+            .iter()
+            .fold(0, |acc, batch| acc + batch.get_array_memory_size())
+    }
+
     #[getter]
     pub fn num_columns(&self) -> usize {
         self.schema.fields().len()