zarr-developers · mwlon · Feb 12, 2026 · Feb 12, 2026 · Feb 12, 2026 · Feb 12, 2026
diff --git a/fixture/pcodec/codec.10/config.json b/fixture/pcodec/codec.10/config.json
@@ -0,0 +1,9 @@
+{
+    "delta_encoding_order": null,
+    "delta_spec": "no_op",
+    "equal_pages_up_to": 262144,
+    "id": "pcodec",
+    "level": 8,
+    "mode_spec": "auto",
+    "paging_spec": "equal_pages_up_to"
+}
diff --git a/fixture/pcodec/codec.10/encoded.00.dat b/fixture/pcodec/codec.10/encoded.00.dat
diff --git a/fixture/pcodec/codec.10/encoded.01.dat b/fixture/pcodec/codec.10/encoded.01.dat
diff --git a/fixture/pcodec/codec.10/encoded.02.dat b/fixture/pcodec/codec.10/encoded.02.dat
diff --git a/fixture/pcodec/codec.10/encoded.03.dat b/fixture/pcodec/codec.10/encoded.03.dat
diff --git a/fixture/pcodec/codec.10/encoded.04.dat b/fixture/pcodec/codec.10/encoded.04.dat
diff --git a/fixture/pcodec/codec.10/encoded.05.dat b/fixture/pcodec/codec.10/encoded.05.dat
diff --git a/fixture/pcodec/codec.10/encoded.06.dat b/fixture/pcodec/codec.10/encoded.06.dat
diff --git a/fixture/pcodec/codec.10/encoded.07.dat b/fixture/pcodec/codec.10/encoded.07.dat
diff --git a/fixture/pcodec/codec.10/encoded.08.dat b/fixture/pcodec/codec.10/encoded.08.dat
diff --git a/fixture/pcodec/codec.10/encoded.09.dat b/fixture/pcodec/codec.10/encoded.09.dat
diff --git a/numcodecs/pcodec.py b/numcodecs/pcodec.py
@@ -27,9 +27,10 @@ class PCodec(Codec):
         structure of the data (e.g. approximate multiples of 0.1) to improve
         compression ratio, or skip this step and just use the numbers as-is
         (Classic mode). Note that the "try*" specs are not currently supported.
-    delta_spec : {"auto", "none", "try_consecutive", "try_lookback"}
+    delta_spec : {"auto", "no_op", "none", "try_consecutive", "try_lookback"}
         Configures the delta encoding strategy. By default, uses "auto" which
-        will try to infer the best encoding order.
+        will try to infer the best encoding order. "none" is equivalent to
+        "no_op" and may be removed in the future.
     paging_spec : {"equal_pages_up_to"}
         Configures the paging strategy. Only "equal_pages_up_to" is currently
         supported.
@@ -48,7 +49,7 @@ def __init__(
         level: int = 8,
         *,
         mode_spec: Literal["auto", "classic"] = "auto",
-        delta_spec: Literal["auto", "none", "try_consecutive", "try_lookback"] = "auto",
+        delta_spec: Literal["auto", "no_op", "none", "try_consecutive", "try_lookback"] = "auto",
         paging_spec: Literal["equal_pages_up_to"] = "equal_pages_up_to",
         delta_encoding_order: int | None = None,
         equal_pages_up_to: int = DEFAULT_MAX_PAGE_N,
@@ -82,8 +83,8 @@ def _get_chunk_config(self):
             match self.delta_spec:
                 case "auto":
                     delta_spec = DeltaSpec.auto()
-                case "none":
-                    delta_spec = DeltaSpec.none()
+                case "no_op" | "none":  # legacy support for "none"
+                    delta_spec = DeltaSpec.no_op()
                 case "try_consecutive":
                     delta_spec = DeltaSpec.try_consecutive(self.delta_encoding_order)
                 case "try_lookback":

diff --git a/numcodecs/tests/test_pcodec.py b/numcodecs/tests/test_pcodec.py
@@ -26,6 +26,7 @@
     PCodec(delta_spec="try_lookback"),
     PCodec(delta_spec="none"),
     PCodec(delta_spec="try_consecutive", delta_encoding_order=1),
+    PCodec(delta_spec="no_op"),
 ]
 
 

diff --git a/pyproject.toml b/pyproject.toml
@@ -54,7 +54,7 @@ zfpy = [
     "zfpy>=1.0.0"
 ]
 pcodec = [
-    "pcodec>=0.3,<0.4",
+    "pcodec>=1,<2",
 ]
 crc32c = [
     "crc32c>=2.7",