From fe590dfae33ee7d095d019df454045d96bfe7ef3 Mon Sep 17 00:00:00 2001
From: Stijn de Gooijer <stijn@degooijer.io>
Date: Mon, 9 Oct 2023 14:30:25 +0200
Subject: [PATCH] depr(python): Deprecate default value for `radix` in
 `parse_int`

---
 py-polars/polars/expr/string.py                | 15 +++++++++++----
 py-polars/polars/series/string.py              |  8 +++-----
 py-polars/tests/unit/namespaces/test_string.py |  8 ++++++++
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/py-polars/polars/expr/string.py b/py-polars/polars/expr/string.py
index 5ae5708f27bc..a43e96445929 100644
--- a/py-polars/polars/expr/string.py
+++ b/py-polars/polars/expr/string.py
@@ -11,6 +11,7 @@
 from polars.utils._wrap import wrap_expr
 from polars.utils.deprecation import (
     deprecate_renamed_function,
+    issue_deprecation_warning,
     rename_use_earliest_to_ambiguous,
 )
 from polars.utils.various import find_stacklevel
@@ -1917,18 +1918,16 @@ def explode(self) -> Expr:
         """
         return wrap_expr(self._pyexpr.str_explode())
 
-    def parse_int(self, radix: int = 2, *, strict: bool = True) -> Expr:
+    def parse_int(self, radix: int | None = None, *, strict: bool = True) -> Expr:
         """
         Parse integers with base radix from strings.
 
-        By default base 2. ParseError/Overflows become Nulls.
+        ParseError/Overflows become Nulls.
 
         Parameters
         ----------
         radix
             Positive integer which is the base of the string we are parsing.
-            Default: 2.
-
         strict
             Bool, Default=True will raise any ParseError or overflow as ComputeError.
             False silently convert to Null.
@@ -1969,6 +1968,14 @@ def parse_int(self, radix: int = 2, *, strict: bool = True) -> Expr:
         └───────┘
 
         """
+        if radix is None:
+            issue_deprecation_warning(
+                "The default value for the `radix` parameter of `parse_int` will be removed in a future version."
+                " Call `parse_int(radix=2)` to keep current behavior and silence this warning.",
+                version="0.19.8",
+            )
+            radix = 2
+
         return wrap_expr(self._pyexpr.str_parse_int(radix, strict))
 
     @deprecate_renamed_function("strip_chars", version="0.19.3")
diff --git a/py-polars/polars/series/string.py b/py-polars/polars/series/string.py
index 777daa8fd92e..ff484633c98e 100644
--- a/py-polars/polars/series/string.py
+++ b/py-polars/polars/series/string.py
@@ -1457,18 +1457,16 @@ def explode(self) -> Series:
 
         """
 
-    def parse_int(self, radix: int = 2, *, strict: bool = True) -> Series:
-        r"""
+    def parse_int(self, radix: int | None = None, *, strict: bool = True) -> Series:
+        """
         Parse integers with base radix from strings.
 
-        By default base 2. ParseError/Overflows become Nulls.
+        ParseError/Overflows become Nulls.
 
         Parameters
         ----------
         radix
             Positive integer which is the base of the string we are parsing.
-            Default: 2
-
         strict
             Bool, Default=True will raise any ParseError or overflow as ComputeError.
             False silently convert to Null.
diff --git a/py-polars/tests/unit/namespaces/test_string.py b/py-polars/tests/unit/namespaces/test_string.py
index fba1c8c458b1..fce10f852d63 100644
--- a/py-polars/tests/unit/namespaces/test_string.py
+++ b/py-polars/tests/unit/namespaces/test_string.py
@@ -205,6 +205,14 @@ def test_str_parse_int_df() -> None:
         )
 
 
+def test_str_parse_int_deprecated_default() -> None:
+    s = pl.Series(["110", "101", "010"])
+    with pytest.deprecated_call(match="default value"):
+        result = s.str.parse_int()
+    expected = pl.Series([6, 5, 2], dtype=pl.Int32)
+    assert_series_equal(result, expected)
+
+
 def test_str_strip_chars_expr() -> None:
     df = pl.DataFrame(
         {