MIN: forward variable name down to coders for CharacterArrayCoder

pydata · kmuehlbauer · Jun 20, 2025 · Jun 4, 2025 · Jun 4, 2025 · Jun 4, 2025
commit e01580aefa89abe9dcb26d4e03fd58a7fba9e7f7
diff --git a/xarray/backends/common.py b/xarray/backends/common.py
@@ -389,11 +389,11 @@ def encode(self, variables, attributes):
         attributes : dict-like
 
         """
-        variables = {k: self.encode_variable(v) for k, v in variables.items()}
+        variables = {k: self.encode_variable(v, name=k) for k, v in variables.items()}
         attributes = {k: self.encode_attribute(v) for k, v in attributes.items()}
         return variables, attributes
 
-    def encode_variable(self, v):
+    def encode_variable(self, v, name=None):
         """encode one variable"""
         return v
 
@@ -641,7 +641,7 @@ def encode(self, variables, attributes):
         variables = {
             k: ensure_dtype_not_object(v, name=k) for k, v in variables.items()
         }
-        variables = {k: self.encode_variable(v) for k, v in variables.items()}
+        variables = {k: self.encode_variable(v, name=k) for k, v in variables.items()}
         attributes = {k: self.encode_attribute(v) for k, v in attributes.items()}
         return variables, attributes
 

diff --git a/xarray/backends/h5netcdf_.py b/xarray/backends/h5netcdf_.py
@@ -286,8 +286,8 @@ def set_dimension(self, name, length, is_unlimited=False):
     def set_attribute(self, key, value):
         self.ds.attrs[key] = value
 
-    def encode_variable(self, variable):
-        return _encode_nc4_variable(variable)
+    def encode_variable(self, variable, name=None):
+        return _encode_nc4_variable(variable, name=name)
 
     def prepare_variable(
         self, name, variable, check_encoding=False, unlimited_dims=None

diff --git a/xarray/backends/netCDF4_.py b/xarray/backends/netCDF4_.py
@@ -9,7 +9,6 @@
 
 import numpy as np
 
-from xarray import coding
 from xarray.backends.common import (
     BACKEND_ENTRYPOINTS,
     BackendArray,
@@ -30,6 +29,12 @@
 )
 from xarray.backends.netcdf3 import encode_nc3_attr_value, encode_nc3_variable
 from xarray.backends.store import StoreBackendEntrypoint
+from xarray.coding.strings import (
+    CharacterArrayCoder,
+    EncodedStringCoder,
+    create_vlen_dtype,
+    is_unicode_dtype,
+)
 from xarray.coding.variables import pop_to
 from xarray.core import indexing
 from xarray.core.utils import (
@@ -73,7 +78,7 @@ def __init__(self, variable_name, datastore):
             # check vlen string dtype in further steps
             # it also prevents automatic string concatenation via
             # conventions.decode_cf_variable
-            dtype = coding.strings.create_vlen_dtype(str)
+            dtype = create_vlen_dtype(str)
         self.dtype = dtype
 
     def __setitem__(self, key, value):
@@ -127,12 +132,12 @@ def _getitem(self, key):
         return array
 
 
-def _encode_nc4_variable(var):
+def _encode_nc4_variable(var, name=None):
     for coder in [
-        coding.strings.EncodedStringCoder(allows_unicode=True),
-        coding.strings.CharacterArrayCoder(),
+        EncodedStringCoder(allows_unicode=True),
+        CharacterArrayCoder(),
     ]:
-        var = coder.encode(var)
+        var = coder.encode(var, name=name)
     return var
 
 
@@ -164,7 +169,7 @@ def _nc4_dtype(var):
     if "dtype" in var.encoding:
         dtype = var.encoding.pop("dtype")
         _check_encoding_dtype_is_vlen_string(dtype)
-    elif coding.strings.is_unicode_dtype(var.dtype):
+    elif is_unicode_dtype(var.dtype):
         dtype = str
     elif var.dtype.kind in ["i", "u", "f", "c", "S"]:
         dtype = var.dtype
@@ -535,12 +540,12 @@ def set_attribute(self, key, value):
         else:
             self.ds.setncattr(key, value)
 
-    def encode_variable(self, variable):
+    def encode_variable(self, variable, name=None):
         variable = _force_native_endianness(variable)
         if self.format == "NETCDF4":
-            variable = _encode_nc4_variable(variable)
+            variable = _encode_nc4_variable(variable, name=name)
         else:
-            variable = encode_nc3_variable(variable)
+            variable = encode_nc3_variable(variable, name=name)
         return variable
 
     def prepare_variable(

diff --git a/xarray/backends/netcdf3.py b/xarray/backends/netcdf3.py
@@ -118,12 +118,12 @@ def _maybe_prepare_times(var):
     return data
 
 
-def encode_nc3_variable(var):
+def encode_nc3_variable(var, name=None):
     for coder in [
         coding.strings.EncodedStringCoder(allows_unicode=False),
         coding.strings.CharacterArrayCoder(),
     ]:
-        var = coder.encode(var)
+        var = coder.encode(var, name=name)
     data = _maybe_prepare_times(var)
     data = coerce_nc3_dtype(data)
     attrs = encode_nc3_attrs(var.attrs)

diff --git a/xarray/backends/scipy_.py b/xarray/backends/scipy_.py
@@ -227,8 +227,8 @@ def set_attribute(self, key, value):
         value = encode_nc3_attr_value(value)
         setattr(self.ds, key, value)
 
-    def encode_variable(self, variable):
-        variable = encode_nc3_variable(variable)
+    def encode_variable(self, variable, name=None):
+        variable = encode_nc3_variable(variable, name=name)
         return variable
 
     def prepare_variable(

diff --git a/xarray/backends/zarr.py b/xarray/backends/zarr.py
@@ -916,8 +916,8 @@ def set_dimensions(self, variables, unlimited_dims=None):
     def set_attributes(self, attributes):
         _put_attrs(self.zarr_group, attributes)
 
-    def encode_variable(self, variable):
-        variable = encode_zarr_variable(variable)
+    def encode_variable(self, variable, name=None):
+        variable = encode_zarr_variable(variable, name=name)
         return variable
 
     def encode_attribute(self, a):