From c818c92fca183fbd73f35a489e64c3568a784c67 Mon Sep 17 00:00:00 2001
From: Iain Russell <Iain.Russell@ecmwf.int>
Date: Wed, 28 Oct 2026 17:01:14 +0000
Subject: [PATCH] Fix sorting of ensemble members in fieldsets [MPY-408]

---
 metview/metviewpy/indexdb.py |  2 +-
 metview/metviewpy/indexer.py |  2 +-
 metview/metviewpy/param.py   |  4 ++--
 tests/test_indexer.py        | 35 ++++++++++++++++++++++++++++++-----
 4 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/metview/metviewpy/indexdb.py b/metview/metviewpy/indexdb.py
index 860102d..259a504 100644
--- a/metview/metviewpy/indexdb.py
+++ b/metview/metviewpy/indexdb.py
@@ -473,7 +473,7 @@ def ls(self, extra_keys=None, filter=None, no_print=False):
             r = df["number"].unique()
             skip = False
             if len(r) == 1:
-                skip = r[0] in ["0", None]
+                skip = r[0] in [0, "0", None]
             if skip:
                 df.drop("number", axis=1, inplace=True)
 
diff --git a/metview/metviewpy/indexer.py b/metview/metviewpy/indexer.py
index e94ed72..a901c2d 100644
--- a/metview/metviewpy/indexer.py
+++ b/metview/metviewpy/indexer.py
@@ -45,7 +45,7 @@ class GribIndexer:
         "step": ("l", "Int32", int, True),
         "level": ("l", "Int32", int, True),
         "typeOfLevel": ("s", str, str, False),
-        "number": ("s", str, str, True),
+        "number": ("l", "Int32", int, True),
         "experimentVersionNumber": ("s", str, str, False),
         "marsClass": ("s", str, str, False),
         "marsStream": ("s", str, str, False),
diff --git a/metview/metviewpy/param.py b/metview/metviewpy/param.py
index 7ba5033..637a5af 100644
--- a/metview/metviewpy/param.py
+++ b/metview/metviewpy/param.py
@@ -349,7 +349,7 @@ def describe(db, param=None, no_print=False):
             t = {"parameter": [], "typeOfLevel": [], "level": []}
             need_number = False
             for k, v in db.param_meta.items():
-                if not v.md.get("number", None) in [["0"], [None]]:
+                if not v.md.get("number", None) in [[0], ["0"], [None]]:
                     need_number = True
                     break
 
@@ -437,7 +437,7 @@ def describe(db, param=None, no_print=False):
                 cnt += 1
 
             for kk, md_v in v.md.items():
-                if kk == "number" and md_v == ["0"]:
+                if kk == "number" and md_v == [0]:
                     continue
                 if not kk in ["shortName", "paramId"]:
                     t["key"].append(labels.get(kk, kk))
diff --git a/tests/test_indexer.py b/tests/test_indexer.py
index 396d9bb..7fc0cde 100644
--- a/tests/test_indexer.py
+++ b/tests/test_indexer.py
@@ -737,7 +737,7 @@ def test_param_info_from_fs_single_file():
         "step": 0,
         "level": 700,
         "typeOfLevel": "isobaricInhPa",
-        "number": "0",
+        "number": 0,
         "experimentVersionNumber": "0001",
         "marsClass": "od",
         "marsStream": "oper",
@@ -759,7 +759,7 @@ def test_param_info_from_fs_single_file():
         "step": 0,
         "level": 500,
         "typeOfLevel": "isobaricInhPa",
-        "number": "0",
+        "number": 0,
         "experimentVersionNumber": "0001",
         "marsClass": "od",
         "marsStream": "oper",
@@ -783,7 +783,7 @@ def test_param_info_from_fs_single_file():
         "step": 0,
         "level": 500,
         "typeOfLevel": "isobaricInhPa",
-        "number": "0",
+        "number": 0,
         "experimentVersionNumber": "0001",
         "marsClass": "od",
         "marsStream": "oper",
@@ -804,7 +804,7 @@ def test_param_info_from_fs_single_file():
         "step": 0,
         "level": None,
         "typeOfLevel": "isobaricInhPa",
-        "number": "0",
+        "number": 0,
         "experimentVersionNumber": "0001",
         "marsClass": "od",
         "marsStream": "oper",
@@ -827,7 +827,7 @@ def test_param_info_from_fs_single_file():
         "step": 0,
         "level": 1000,
         "typeOfLevel": "isobaricInhPa",
-        "number": "0",
+        "number": 0,
         "experimentVersionNumber": "0001",
         "marsClass": "od",
         "marsStream": "oper",
@@ -911,6 +911,31 @@ def test_indexer_dataframe_sort_value_with_key():
         assert False
 
 
+def test_indexer_dataframe_sort_ens():
+
+    md = {
+        "paramId": [5, 5, 5, 5],
+        "level": [925, 925, 925, 925],
+        "step": [12, 12, 12, 12],
+        "number": [1, 9, 10, 20],
+    }
+
+    md_ref = {
+        "paramId": [5, 5, 5, 5],
+        "level": [925, 925, 925, 925],
+        "step": [12, 12, 12, 12],
+        "number": [1, 9, 10, 20],
+   }
+
+    df = pd.DataFrame(md)
+    df = GribIndexer._sort_dataframe(df)
+    df_ref = pd.DataFrame(md_ref)
+
+    if not df.equals(df_ref):
+        print(df.compare(df_ref))
+        assert False
+
+
 def test_describe():
 
     f = mv.read(file_in_testdir("tuv_pl.grib"))