feat(catalog): Prepare existing catalog APIs for integration [1/3]

daft/catalog/__iceberg.py

@@ -0,0 +1,72 @@
+"""WARNING! These APIs are internal; please use Catalog.from_iceberg() and Table.from_iceberg()."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from pyiceberg.catalog import Catalog as InnerCatalog
+from pyiceberg.table import Table as InnerTable
+
+from daft.catalog import Catalog, Table
+
+if TYPE_CHECKING:
+    from daft.dataframe import DataFrame
+
+
+class IcebergCatalog(Catalog):
+    _inner: InnerCatalog
+
+    def __init__(self, pyiceberg_catalog: InnerCatalog):
+        """DEPRECATED: Please use `Catalog.from_iceberg`."""
+        self._inner = pyiceberg_catalog
+
+    @staticmethod
+    def _try_from(obj: object) -> IcebergCatalog | None:
+        """Returns an IcebergCatalog instance if the given object can be adapted so."""
+        if isinstance(obj, InnerCatalog):
+            return IcebergCatalog(obj)
+        return None
+
+    @property
+    def inner(self) -> InnerCatalog:
+        """Returns the inner iceberg catalog."""
+        return self._inner
+
+    ###
+    # get_*
+    ###
+
+    def get_table(self, name: str) -> IcebergTable:
+        return IcebergTable(self._inner.load_table(name))
+
+    ###
+    # list_*
+    ###
+
+    def list_tables(self, pattern: str | None = None) -> list[str]:
+        namespace = pattern if pattern else ""  # pyiceberg lists on namespaces
+        return [".".join(tup) for tup in self._inner.list_tables(namespace)]
+
+
+class IcebergTable(Table):
+    _inner: InnerTable
+
+    def __init__(self, inner: InnerTable):
+        self._inner = inner
+
+    @staticmethod
+    def _try_from(obj: object) -> IcebergTable | None:
+        """Returns an IcebergTable if the given object can be adapted so."""
+        if isinstance(obj, InnerTable):
+            return IcebergTable(obj)
+        return None
+
+    @property
+    def inner(self) -> InnerTable:
+        """Returns the inner iceberg table."""
+        return self._inner
+
+    def read(self) -> DataFrame:
+        import daft
+
+        return daft.read_iceberg(self._inner)

daft/catalog/__init__.py

@@ -1,15 +1,12 @@
-"""The `daft.catalog` module contains functionality for Data Catalogs.
+"""The `daft.catalog` module contains functionality for Catalogs.
 
-A Data Catalog can be understood as a system/service for users to discover, access and query their data.
-Most commonly, users' data is represented as a "table". Some more modern Data Catalogs such as Unity Catalog
+A Catalog can be understood as a system/service for users to discover, access and query their data.
+Most commonly, users' data is represented as a "table". Some more modern Catalogs such as Unity Catalog
 also expose other types of data including files, ML models, registered functions and more.
 
-Examples of Data Catalogs include AWS Glue, Hive Metastore, Apache Iceberg REST and Unity Catalog.
+Examples of Catalogs include AWS Glue, Hive Metastore, Apache Iceberg REST and Unity Catalog.
 
-Daft manages Data Catalogs by registering them in an internal meta-catalog, called the "DaftMetaCatalog". This
-is simple a collection of data catalogs, which Daft will attempt to detect from a users' current environment.
-
-**Data Catalog**
+**Catalog**
 
 Daft recognizes a default catalog which it will attempt to use when no specific catalog name is provided.
 
@@ -20,13 +17,14 @@
 
 **Named Tables**
 
-Daft allows also the registration of named tables, which have no catalog associated with them.
+Daft allows also the registration of temporary tables, which have no catalog associated with them.
 
-Note that named tables take precedence over the default catalog's table names when resolving names.
+Note that temporary tables take precedence over catalog tables when resolving unqualified names.
 
 ```python
 df = daft.from_pydict({"foo": [1, 2, 3]})
 
+# TODO deprecated catalog APIs #3819
 daft.catalog.register_table(
     "my_table",
     df,
@@ -40,31 +38,36 @@
 
 from __future__ import annotations
 
+from abc import ABC, abstractmethod
 from collections.abc import Sequence
 from daft.daft import catalog as native_catalog
+from daft.daft import PyIdentifier
 from daft.logical.builder import LogicalPlanBuilder
 
 from daft.dataframe import DataFrame
 
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from pyiceberg.catalog import Catalog as PyIcebergCatalog
-    from daft.unity_catalog import UnityCatalog
+    from daft.dataframe.dataframe import ColumnInputType
 
 
 __all__ = [
+    "Catalog",
     "Identifier",
+    "Table",
+    # TODO deprecated catalog APIs #3819
     "read_table",
     "register_python_catalog",
     "register_table",
     "unregister_catalog",
 ]
 
-# Forward imports from the native catalog which don't require Python wrappers
+# TODO deprecated catalog APIs #3819
 unregister_catalog = native_catalog.unregister_catalog
 
 
+# TODO deprecated catalog APIs #3819
 def read_table(name: str) -> DataFrame:
     """Finds a table with the specified name and reads it as a DataFrame.
 
@@ -84,6 +87,7 @@
     return DataFrame(LogicalPlanBuilder(native_logical_plan_builder))
 
 
+# TODO deprecated catalog APIs #3819
 def register_table(name: str, dataframe: DataFrame) -> str:
     """Register a DataFrame as a named table.
 
@@ -105,7 +109,8 @@
     return native_catalog.register_table(name, dataframe._builder._builder)
 
 
-def register_python_catalog(catalog: PyIcebergCatalog | UnityCatalog, name: str | None = None) -> str:
+# TODO deprecated catalog APIs #3819
+def register_python_catalog(catalog: object, name: str | None = None) -> str:
     """Registers a Python catalog with Daft.
 
     Currently supports:
@@ -129,35 +134,63 @@
         >>> daft.catalog.register_python_catalog(catalog, "my_daft_catalog")
 
     """
-    _PYICEBERG_AVAILABLE = False
-    try:
-        from pyiceberg.catalog import Catalog as PyIcebergCatalog
+    if (c := Catalog._try_from(catalog)) is not None:
+        return native_catalog.register_python_catalog(c, name)
+    raise ValueError(f"Unsupported catalog type: {type(catalog)}")
+
+
+class Catalog(ABC):
+    """Interface for python catalog implementations."""
 
-        _PYICEBERG_AVAILABLE = True
-    except ImportError:
-        pass
+    @property
+    def inner(self) -> object | None:
+        """Returns the inner catalog object if this is an adapter."""
+
+    @staticmethod
+    def _try_from(obj: object) -> Catalog | None:
+        for factory in (Catalog._try_from_iceberg, Catalog._try_from_unity):
+            if (c := factory(obj)) is not None:
+                return c
+        return None
 
-    _UNITY_AVAILABLE = False
-    try:
-        from daft.unity_catalog import UnityCatalog
+    @staticmethod
+    def _try_from_iceberg(obj: object) -> Catalog | None:
+        """Returns a Daft Catalog instance from an Iceberg catalog."""
+        try:
+            from daft.catalog.__iceberg import IcebergCatalog
+
+            return IcebergCatalog._try_from(obj)
+        except ImportError:
+            return None
+
+    @staticmethod
+    def _try_from_unity(obj: object) -> Catalog | None:
+        """Returns a Daft Catalog instance from a Unity catalog."""
+        try:
+            from daft.catalog.__unity import UnityCatalog
 
-        _UNITY_AVAILABLE = True
-    except ImportError:
-        pass
+            return UnityCatalog._try_from(obj)
+        except ImportError:
+            return None
 
-    python_catalog: PyIcebergCatalog
-    if _PYICEBERG_AVAILABLE and isinstance(catalog, PyIcebergCatalog):
-        from daft.catalog.pyiceberg import PyIcebergCatalogAdaptor
+    ###
+    # list_*
+    ###
 
-        python_catalog = PyIcebergCatalogAdaptor(catalog)
-    elif _UNITY_AVAILABLE and isinstance(catalog, UnityCatalog):
-        from daft.catalog.unity import UnityCatalogAdaptor
+    @abstractmethod
+    def list_tables(self, pattern: str | None = None) -> list[str]: ...
 
-        python_catalog = UnityCatalogAdaptor(catalog)
-    else:
-        raise ValueError(f"Unsupported catalog type: {type(catalog)}")
+    ###
+    # get_*
+    ###
 
-    return native_catalog.register_python_catalog(python_catalog, name)
+    @abstractmethod
+    def get_table(self, name: str) -> Table: ...
+
+    # TODO deprecated catalog APIs #3819
+    def load_table(self, name: str) -> Table:
+        """DEPRECATED: Please use get_table(name: str)."""
+        return self.get_table(name)
 
 
 class Identifier(Sequence):
@@ -168,36 +201,35 @@
     >>> assert len(id) == 2
     """
 
-    _identifier: native_catalog.PyIdentifier
+    _identifier: PyIdentifier
 
     def __init__(self, *parts: str):
         """Creates an Identifier from its parts.
 
         Example:
-        >>> Identifier("schema", "table")
-        >>> #
+        >>> Identifier("namespace", "table")
 
         Returns:
             Identifier: A new identifier.
         """
         if len(parts) < 1:
             raise ValueError("Identifier requires at least one part.")
-        self._identifier = native_catalog.PyIdentifier(parts[:-1], parts[-1])
+        self._identifier = PyIdentifier(parts[:-1], parts[-1])
 
     @staticmethod
     def from_sql(input: str, normalize: bool = False) -> Identifier:
         """Parses an Identifier from an SQL string, normalizing to lowercase if specified.
 
         Example:
-        >>> Identifier.from_sql("schema.table") == Identifier("schema", "table")
+        >>> Identifier.from_sql("namespace.table") == Identifier("namespace", "table")
         >>> Identifier.from_sql('"a.b"') == Identifier('"a.b."')
         >>> Identifier.from_sql('ABC."xYz"', normalize=True) == Identifier("abc", "xYz")
 
         Returns:
             Identifier: A new identifier.
         """
         i = Identifier.__new__(Identifier)
-        i._identifier = native_catalog.PyIdentifier.from_sql(input, normalize)
+        i._identifier = PyIdentifier.from_sql(input, normalize)
         return i
 
     def __eq__(self, other: object) -> bool:
@@ -216,3 +248,28 @@
 
     def __repr__(self) -> str:
         return f"Identifier('{self._identifier.__repr__()}')"
+
+
+class Table(ABC):
+    """Interface for python table implementations."""
+
+    @property
+    def inner(self) -> object | None:
+        """Returns the inner table object if this is an adapter."""
+
+    # TODO deprecated catalog APIs #3819
+    def to_dataframe(self) -> DataFrame:
+        """DEPRECATED: Please use `read()`."""
+        return self.read()
+
+    @abstractmethod
+    def read(self) -> DataFrame:
+        """Returns a DataFrame from this table."""
+
+    def select(self, *columns: ColumnInputType) -> DataFrame:
+        """Returns a DataFrame from this table with the selected columns."""
+        return self.read().select(*columns)
+
+    def show(self, n: int = 8) -> None:
+        """Shows the first n rows from this table."""
+        self.read().show(n)