better expression handling and cleanup

polars_iptools/iptools.py

@@ -72,8 +72,15 @@ def numeric_to_ipv4(expr: IntoExpr) -> pl.Expr:
     """
     Returns IPv4 address string from its numeric representation
     """
+    # Convert to a polars expression if not already one
+    if isinstance(expr, str):
+        expr = pl.col(expr)
+    elif isinstance(expr, pl.Series):
+        expr = pl.lit(expr)
+
     # cast to UInt32 and leave any errors as nulls
-    expr = pl.select(expr).to_series().cast(pl.UInt32, strict=False)
+    expr = expr.cast(pl.UInt32, strict=False)
+
     return register_plugin_function(
         args=[expr],
         plugin_path=LIB,

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["maturin>=1.0,<2.0", "polars>=0.20.6"]
+requires = ["maturin>=1.0,<2.0", "polars>=1.3.0"]
 build-backend = "maturin"
 
 [project]