Cherry pick from apache#1252

Author: ntjohnson1

src/common/data_type.rs

@@ -37,7 +37,7 @@ impl From<PyScalarValue> for ScalarValue {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(eq, eq_int, name = "RexType", module = "datafusion.common")]
+#[pyclass(frozen, eq, eq_int, name = "RexType", module = "datafusion.common")]
 pub enum RexType {
     Alias,
     Literal,
@@ -56,6 +56,7 @@ pub enum RexType {
 /// and manageable location. Therefore this structure exists
 /// to map those types and provide a simple place for developers
 /// to map types from one system to another.
+// TODO: This looks like this needs pyo3 tracking so leaving unfrozen for now
 #[derive(Debug, Clone)]
 #[pyclass(name = "DataTypeMap", module = "datafusion.common", subclass)]
 pub struct DataTypeMap {
@@ -577,7 +578,7 @@ impl DataTypeMap {
 /// Since `DataType` exists in another package we cannot make that happen here so we wrap
 /// `DataType` as `PyDataType` This exists solely to satisfy those constraints.
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(name = "DataType", module = "datafusion.common")]
+#[pyclass(frozen, name = "DataType", module = "datafusion.common")]
 pub struct PyDataType {
     pub data_type: DataType,
 }
@@ -635,7 +636,7 @@ impl From<DataType> for PyDataType {
 
 /// Represents the possible Python types that can be mapped to the SQL types
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(eq, eq_int, name = "PythonType", module = "datafusion.common")]
+#[pyclass(frozen, eq, eq_int, name = "PythonType", module = "datafusion.common")]
 pub enum PythonType {
     Array,
     Bool,
@@ -655,7 +656,7 @@ pub enum PythonType {
 #[allow(non_camel_case_types)]
 #[allow(clippy::upper_case_acronyms)]
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(eq, eq_int, name = "SqlType", module = "datafusion.common")]
+#[pyclass(frozen, eq, eq_int, name = "SqlType", module = "datafusion.common")]
 pub enum SqlType {
     ANY,
     ARRAY,
@@ -713,7 +714,13 @@ pub enum SqlType {
 #[allow(non_camel_case_types)]
 #[allow(clippy::upper_case_acronyms)]
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(eq, eq_int, name = "NullTreatment", module = "datafusion.common")]
+#[pyclass(
+    frozen,
+    eq,
+    eq_int,
+    name = "NullTreatment",
+    module = "datafusion.common"
+)]
 pub enum NullTreatment {
     IGNORE_NULLS,
     RESPECT_NULLS,

src/common/df_schema.rs

@@ -21,7 +21,7 @@ use datafusion::common::DFSchema;
 use pyo3::prelude::*;
 
 #[derive(Debug, Clone)]
-#[pyclass(name = "DFSchema", module = "datafusion.common", subclass)]
+#[pyclass(frozen, name = "DFSchema", module = "datafusion.common", subclass)]
 pub struct PyDFSchema {
     schema: Arc<DFSchema>,
 }

src/common/function.rs

@@ -22,7 +22,7 @@ use pyo3::prelude::*;
 
 use super::data_type::PyDataType;
 
-#[pyclass(name = "SqlFunction", module = "datafusion.common", subclass)]
+#[pyclass(frozen, name = "SqlFunction", module = "datafusion.common", subclass)]
 #[derive(Debug, Clone)]
 pub struct SqlFunction {
     pub name: String,

src/common/schema.rs

@@ -248,7 +248,7 @@ fn is_supported_push_down_expr(_expr: &Expr) -> bool {
     true
 }
 
-#[pyclass(name = "SqlStatistics", module = "datafusion.common", subclass)]
+#[pyclass(frozen, name = "SqlStatistics", module = "datafusion.common", subclass)]
 #[derive(Debug, Clone)]
 pub struct SqlStatistics {
     row_count: f64,
@@ -267,7 +267,7 @@ impl SqlStatistics {
     }
 }
 
-#[pyclass(name = "Constraints", module = "datafusion.expr", subclass)]
+#[pyclass(frozen, name = "Constraints", module = "datafusion.expr", subclass)]
 #[derive(Clone)]
 pub struct PyConstraints {
     pub constraints: Constraints,
@@ -292,7 +292,7 @@ impl Display for PyConstraints {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-#[pyclass(eq, eq_int, name = "TableType", module = "datafusion.common")]
+#[pyclass(frozen, eq, eq_int, name = "TableType", module = "datafusion.common")]
 pub enum PyTableType {
     Base,
     View,
@@ -319,7 +319,7 @@ impl From<TableType> for PyTableType {
     }
 }
 
-#[pyclass(name = "TableSource", module = "datafusion.common", subclass)]
+#[pyclass(frozen, name = "TableSource", module = "datafusion.common", subclass)]
 #[derive(Clone)]
 pub struct PyTableSource {
     pub table_source: Arc<dyn TableSource>,