From e6109a44844875bda2fecc01b6a8c454b10cbdba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20Milenkovi=C4=87?=
 <milenkovicm@users.noreply.github.com>
Date: Tue, 14 Oct 2025 10:50:11 +0100
Subject: [PATCH 1/2] feat: expose DataFrame.parse_sql_expr to python

---
 python/datafusion/dataframe.py | 22 ++++++++++++++++++++++
 python/tests/test_dataframe.py | 25 +++++++++++++++++++++++++
 src/dataframe.rs               |  8 ++++++++
 3 files changed, 55 insertions(+)

diff --git a/python/datafusion/dataframe.py b/python/datafusion/dataframe.py
index 16765656a..86131c45f 100644
--- a/python/datafusion/dataframe.py
+++ b/python/datafusion/dataframe.py
@@ -482,6 +482,28 @@ def filter(self, *predicates: Expr) -> DataFrame:
             df = df.filter(ensure_expr(p))
         return DataFrame(df)
 
+    def parse_sql_expr(self, expr: str) -> Expr:
+        """Creates logical expression from a SQL query text.
+
+        The expression is created and processed against the current schema.
+
+        Example::
+
+            from datafusion import col, lit
+            df.parse_sql_expr("a > 1")
+
+            should produce:
+
+            col("a") > lit(1)
+
+        Args:
+            expr: Expression string to be converted to datafusion expression
+
+        Returns:
+            Logical expression .
+        """
+        return Expr(self.df.parse_sql_expr(expr))
+
     def with_column(self, name: str, expr: Expr) -> DataFrame:
         """Add an additional column to the DataFrame.
 
diff --git a/python/tests/test_dataframe.py b/python/tests/test_dataframe.py
index cd85221c5..41318135d 100644
--- a/python/tests/test_dataframe.py
+++ b/python/tests/test_dataframe.py
@@ -274,6 +274,31 @@ def test_filter(df):
     assert result.column(2) == pa.array([5])
 
 
+def test_parse_sql_expr(df):
+    df1 = df.filter(df.parse_sql_expr("a > 2")).select(
+        column("a") + column("b"),
+        column("a") - column("b"),
+    )
+
+    # execute and collect the first (and only) batch
+    result = df1.collect()[0]
+
+    assert result.column(0) == pa.array([9])
+    assert result.column(1) == pa.array([-3])
+
+    df.show()
+    # verify that if there is no filter applied, internal dataframe is unchanged
+    df2 = df.filter()
+    assert df.df == df2.df
+
+    df3 = df.filter(df.parse_sql_expr("a > 1"), df.parse_sql_expr("b != 6"))
+    result = df3.collect()[0]
+
+    assert result.column(0) == pa.array([2])
+    assert result.column(1) == pa.array([5])
+    assert result.column(2) == pa.array([5])
+
+
 def test_show_empty(df, capsys):
     df_empty = df.filter(column("a") > literal(3))
     df_empty.show()
diff --git a/src/dataframe.rs b/src/dataframe.rs
index c23c0c97f..34da87443 100644
--- a/src/dataframe.rs
+++ b/src/dataframe.rs
@@ -454,6 +454,14 @@ impl PyDataFrame {
         Ok(Self::new(df))
     }
 
+    fn parse_sql_expr(&self, expr: PyBackedStr) -> PyDataFusionResult<PyExpr> {
+        self.df
+            .as_ref()
+            .parse_sql_expr(&expr)
+            .map(|e| PyExpr::from(e))
+            .map_err(PyDataFusionError::from)
+    }
+
     fn with_column(&self, name: &str, expr: PyExpr) -> PyDataFusionResult<Self> {
         let df = self.df.as_ref().clone().with_column(name, expr.into())?;
         Ok(Self::new(df))

From c64a66b3f93d59f2abc47a46960063ff717c2f32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20Milenkovi=C4=87?=
 <milenkovicm@users.noreply.github.com>
Date: Tue, 14 Oct 2025 14:56:08 +0100
Subject: [PATCH 2/2] Update python/tests/test_dataframe.py

Co-authored-by: Tim Saucer <timsaucer@gmail.com>
---
 python/tests/test_dataframe.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/python/tests/test_dataframe.py b/python/tests/test_dataframe.py
index 41318135d..76b808038 100644
--- a/python/tests/test_dataframe.py
+++ b/python/tests/test_dataframe.py
@@ -275,6 +275,11 @@ def test_filter(df):
 
 
 def test_parse_sql_expr(df):
+    plan1 = df.filter(df.parse_sql_expr("a > 2")).logical_plan()
+    plan2 = df.filter(column("a") > literal(2)).logical_plan()
+    # object equality not implemented but string representation should match
+    assert str(plan1) == str(plan2)
+
     df1 = df.filter(df.parse_sql_expr("a > 2")).select(
         column("a") + column("b"),
         column("a") - column("b"),