fix(deps): silence polars explode() empty_as_null deprecation warnings

pytest emitted 113 DeprecationWarnings, all from the same source: polars
2.0 changes explode()'s default handling of empty lists from "explode to
null" to "drop the row". Every explode() call site in this repo already
follows the explode with drop_nulls() (or otherwise excludes empty
lists), so the new behavior is what we always wanted — pass
empty_as_null=False explicitly rather than suppressing the warning.

Bump the polars floor from >=1.0 to >=1.43, since the empty_as_null
kwarg doesn't exist before ~1.35.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012dE2r7cNo9Lbthh1JUW1NF

giant/analysis/prediction.py

@@ -275,7 +275,7 @@ def prediction_secondaries(lf: pl.LazyFrame, prefix: str) -> pl.LazyFrame:
     lists = [f"{col_prefix}sec_{c}_list" for c in ("E", "pdg", "dx", "dy", "dz")]
     return (
         lf.select("event_id", *lists)
-        .explode(lists)
+        .explode(lists, empty_as_null=False)
         .drop_nulls(lists[0])
         .select(
             "event_id",
@@ -307,7 +307,7 @@ def paired_secondaries(lf: pl.LazyFrame) -> pl.LazyFrame:
         .with_columns(pl.min_horizontal("_n_true", "_n_pred").alias("_n_paired"))
         .filter(pl.col("_n_paired") > 0)
         .with_columns(pl.int_ranges(0, pl.col("_n_paired")).alias("_rank"))
-        .explode("_rank")
+        .explode("_rank", empty_as_null=False)
         .select(
             pl.col("true_sec_pdg_list").list.get(pl.col("_rank")).cast(pl.Int64).alias("true_pdg"),
             pl.col("sec_pdg_list").list.get(pl.col("_rank")).cast(pl.Int64).alias("pred_pdg"),

giant/analysis/sources.py

@@ -230,7 +230,7 @@ def secondaries(lf: pl.LazyFrame, side: Side) -> pl.LazyFrame:
     lists = ["sec_E_list", "sec_pdg_list", "sec_dx_list", "sec_dy_list", "sec_dz_list"]
     return (
         lf.select("event_id", *lists)
-        .explode(lists)
+        .explode(lists, empty_as_null=False)
         .drop_nulls("sec_E_list")
         .select(
             "event_id",
@@ -268,7 +268,7 @@ def secondaries_by_step(lf: pl.LazyFrame, side: Side) -> pl.LazyFrame:
     return (
         lf.select("sec_pdg_list")
         .with_row_index("_row")
-        .explode("sec_pdg_list")
+        .explode("sec_pdg_list", empty_as_null=False)
         .drop_nulls("sec_pdg_list")
         .select(pl.struct("_row").alias("step_key"), pl.col("sec_pdg_list").cast(pl.Int64).alias("pdg"))
     )

giant/data/scan.py

@@ -76,7 +76,11 @@ def _pooled_pdg_lazy(path: Path, has_sec_pdg_list: bool) -> pl.LazyFrame:
     lf = pl.scan_parquet(path, row_index_name="__row")
     parts = [lf.select(pl.col("pdg").alias("__val"), "__row")]
     if has_sec_pdg_list:
-        parts.append(lf.select(pl.col("sec_pdg_list").alias("__val"), "__row").explode("__val").drop_nulls("__val"))
+        parts.append(
+            lf.select(pl.col("sec_pdg_list").alias("__val"), "__row")
+            .explode("__val", empty_as_null=False)
+            .drop_nulls("__val")
+        )
     combined = pl.concat(parts)
     return combined.group_by("__val").agg(pl.len().alias("__count"), pl.col("__row").min().alias("__first_row"))
 

giant/tools/steps_to_parquet.py

@@ -58,7 +58,7 @@ def _add_secondary_attributes(df: pl.DataFrame) -> tuple[pl.DataFrame, int]:
     exploded = (
         df.select(["event_id", "child_track_ids"])
         .with_row_index("_step_row")
-        .explode("child_track_ids")
+        .explode("child_track_ids", empty_as_null=False)
         .rename({"child_track_ids": "child_track_id"})
         .drop_nulls("child_track_id")
     )

pyproject.toml

@@ -6,7 +6,7 @@ readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
     "numpy>=1.26,<3",
-    "polars>=1.0,<2",
+    "polars>=1.43,<2",
     "pyarrow>=16,<26",
     "tqdm>=4.60,<5",
     "typer>=0.12,<1",
@@ -43,11 +43,11 @@ wandb = [
 convert = [
     "uproot>=5.3,<6",
     "awkward>=2.6,<3",
-    "polars>=1.0,<2",
+    "polars>=1.43,<2",
 ]
 analysis = [
     "matplotlib>=3.8,<4",
-    "polars>=1.0,<2",
+    "polars>=1.43,<2",
     "ipykernel>=7.3.0",
     # KIT matplotlib theme, published from git.larsbogner.de. Only the local
     # `giant analyze render` step imports it; compute workers never do.

uv.lock

@@ -892,9 +892,9 @@ requires-dist = [
     { name = "pandas", marker = "extra == 'dev'", specifier = ">=2.2,<4" },
     { name = "particle", specifier = ">=1.0,<2" },
     { name = "plotstyle", marker = "extra == 'analysis'", specifier = ">=1.0.0", index = "https://git.larsbogner.de/api/packages/lars/pypi/simple/" },
-    { name = "polars", specifier = ">=1.0,<2" },
-    { name = "polars", marker = "extra == 'analysis'", specifier = ">=1.0,<2" },
-    { name = "polars", marker = "extra == 'convert'", specifier = ">=1.0,<2" },
+    { name = "polars", specifier = ">=1.43,<2" },
+    { name = "polars", marker = "extra == 'analysis'", specifier = ">=1.43,<2" },
+    { name = "polars", marker = "extra == 'convert'", specifier = ">=1.43,<2" },
     { name = "pyarrow", specifier = ">=16,<26" },
     { name = "pytest", marker = "extra == 'dev'", specifier = ">=8,<10" },
     { name = "pytest-cov", marker = "extra == 'dev'", specifier = ">=5,<8" },