fix(python): use json for expr pickle (#5476)

pola-rs · Nov 11, 2022 · 1f642ee · 1f642ee
1 parent 0c94ae5
commit 1f642ee
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/py-polars/src/lazy/dsl.rs b/py-polars/src/lazy/dsl.rs
@@ -79,7 +79,8 @@ impl PyExpr {
 
     pub fn __getstate__(&self, py: Python) -> PyResult<PyObject> {
         // Used in pickle/pickling
-        Ok(PyBytes::new(py, &bincode::serialize(&self.inner).unwrap()).to_object(py))
+        let s = serde_json::to_string(&self.inner).unwrap();
+        Ok(PyBytes::new(py, s.as_bytes()).to_object(py))
     }
 
     pub fn __setstate__(&mut self, py: Python, state: PyObject) -> PyResult<()> {
@@ -93,8 +94,8 @@ impl PyExpr {
                 // PyBytes still has a lifetime. Bit its ok, because we drop it immediately
                 // in this scope
                 let s = unsafe { std::mem::transmute::<&'_ PyBytes, &'static PyBytes>(s) };
+                self.inner = serde_json::from_slice(s.as_bytes()).unwrap();
 
-                self.inner = bincode::deserialize(s.as_bytes()).unwrap();
                 Ok(())
             }
             Err(e) => Err(e),

diff --git a/py-polars/tests/unit/test_serde.py b/py-polars/tests/unit/test_serde.py
@@ -56,3 +56,8 @@ def test_serde_duration() -> None:
         serde_df["a_td"],
         pl.Series("a_td", [None, timedelta(days=1)], dtype=pl.Duration("ns")),
     )
+
+
+def test_serde_expression_5461() -> None:
+    e = pl.col("a").sqrt() / pl.col("b").alias("c")
+    assert pickle.loads(pickle.dumps(e)).meta == e.meta