depr(dask,pandas): deprecate the dask and pandas backends

docs/_tabsets/install.qmd

@@ -10,7 +10,6 @@ from textwrap import dedent
 backends = [
     {"name": "BigQuery", "module": "bigquery"},
     {"name": "ClickHouse", "module": "clickhouse"},
-    {"name": "Dask", "module": "dask"},
     {"name": "DataFusion", "module": "datafusion"},
     {"name": "Druid", "module": "druid"},
     {"name": "DuckDB", "module": "duckdb"},
@@ -20,7 +19,6 @@ backends = [
     {"name": "MSSQL", "module": "mssql"},
     {"name": "MySQL", "module": "mysql"},
     {"name": "Oracle", "module": "oracle"},
-    {"name": "pandas", "module": "pandas"},
     {"name": "Polars", "module": "polars"},
     {"name": "PostgreSQL", "module": "postgres"},
     {"name": "PySpark", "module": "pyspark"},

docs/backends/dask.qmd

@@ -4,6 +4,13 @@
 
 ![](https://img.shields.io/badge/memtables-native-green?style=flat-square) ![](https://img.shields.io/badge/inputs-CSV | Parquet-blue?style=flat-square) ![](https://img.shields.io/badge/outputs-CSV | pandas | Parquet | PyArrow-orange?style=flat-square)
 
+::: {.callout-warning}
+## The Dask backend is slated for removal in Ibis 10.0
+We recommend using one of our other backends.
+
+Many workloads work well on the DuckDB and Polars backends, for example.
+:::
+
 ## Install
 
 Install Ibis and dependencies for the Dask backend:

docs/backends/pandas.qmd

@@ -4,6 +4,14 @@
 
 ![](https://img.shields.io/badge/memtables-native-green?style=flat-square) ![](https://img.shields.io/badge/inputs-CSV | Parquet-blue?style=flat-square) ![](https://img.shields.io/badge/outputs-CSV | pandas | Parquet | PyArrow-orange?style=flat-square)
 
+::: {.callout-warning}
+## The Pandas backend is slated for removal in Ibis 10.0
+We recommend using one of our other backends.
+
+Many workloads work well on the DuckDB and Polars backends, for example.
+:::
+
+
 ## Install
 
 Install Ibis and dependencies for the pandas backend:

ibis/backends/dask/__init__.py

@@ -48,16 +48,14 @@ def do_connect(
         >>> ibis.dask.connect(data)
 
         """
-        if dictionary is None:
-            dictionary = {}
+        super().do_connect(dictionary)
 
-        for k, v in dictionary.items():
+        for k, v in self.dictionary.items():
             if not isinstance(v, (dd.DataFrame, pd.DataFrame)):
                 raise TypeError(
                     f"Expected an instance of 'dask.dataframe.DataFrame' for {k!r},"
                     f" got an instance of '{type(v).__name__}' instead."
                 )
-        super().do_connect(dictionary)
 
     def disconnect(self) -> None:
         pass

ibis/backends/pandas/__init__.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import warnings
 from functools import lru_cache
 from typing import TYPE_CHECKING, Any
 
@@ -51,6 +52,10 @@ def do_connect(
         <ibis.backends.pandas.Backend at 0x...>
 
         """
+        warnings.warn(
+            f"The {self.name} backend is slated for removal in 10.0.",
+            DeprecationWarning,
+        )
         self.dictionary = dictionary or {}
         self.schemas: MutableMapping[str, sch.Schema] = {}
 

pyproject.toml

@@ -385,6 +385,8 @@ filterwarnings = [
   "ignore:Passing a BlockManager to DataFrame is deprecated:DeprecationWarning",
   # snowpark logging warnings
   "ignore:The 'warn' method is deprecated, use 'warning' instead:DeprecationWarning",
+  # dask and pandas backend deprecation
+  'ignore:The (dask|pandas) backend is slated for removal in 10\.0:DeprecationWarning',
 ]
 empty_parameter_set_mark = "fail_at_collect"
 markers = [