Automatically convert pydantic model (#400)

Saves users from having to explicitly call
`LanceModel.to_arrow_schema()` when creating an empty table.
See new docs for full details.

---------

Co-authored-by: Chang She <chang@lancedb.com>

python/lancedb/db.py

@@ -22,6 +22,7 @@ import pyarrow as pa
 from pyarrow import fs
 
 from .common import DATA, URI
+from .pydantic import LanceModel
 from .table import LanceTable, Table
 from .util import fs_from_uri, get_uri_location, get_uri_scheme
 
@@ -39,7 +40,7 @@ class DBConnection(ABC):
         self,
         name: str,
         data: Optional[DATA] = None,
-        schema: Optional[pa.Schema] = None,
+        schema: Optional[pa.Schema, LanceModel] = None,
         mode: str = "create",
         on_bad_vectors: str = "error",
         fill_value: float = 0.0,
@@ -52,7 +53,7 @@ class DBConnection(ABC):
             The name of the table.
         data: list, tuple, dict, pd.DataFrame; optional
             The data to initialize the table. User must provide at least one of `data` or `schema`.
-        schema: pyarrow.Schema; optional
+        schema: pyarrow.Schema or LanceModel; optional
             The schema of the table.
         mode: str; default "create"
             The mode to use when creating the table. Can be either "create" or "overwrite".
@@ -277,7 +278,7 @@ class LanceDBConnection(DBConnection):
         self,
         name: str,
         data: Optional[DATA] = None,
-        schema: pa.Schema = None,
+        schema: Optional[pa.Schema, LanceModel] = None,
         mode: str = "create",
         on_bad_vectors: str = "error",
         fill_value: float = 0.0,

python/lancedb/table.py

@@ -13,6 +13,7 @@
 
 from __future__ import annotations
 
+import inspect
 import os
 from abc import ABC, abstractmethod
 from functools import cached_property
@@ -506,7 +507,7 @@ class LanceTable(Table):
         data: list-of-dict, dict, pd.DataFrame, default None
             The data to insert into the table.
             At least one of `data` or `schema` must be provided.
-        schema: dict, optional
+        schema: pa.Schema or LanceModel, optional
             The schema of the table. If not provided, the schema is inferred from the data.
             At least one of `data` or `schema` must be provided.
         mode: str, default "create"
@@ -519,6 +520,8 @@ class LanceTable(Table):
             The value to use when filling vectors. Only used if on_bad_vectors="fill".
         """
         tbl = LanceTable(db, name)
+        if inspect.isclass(schema) and issubclass(schema, LanceModel):
+            schema = schema.to_arrow_schema()
         if data is not None:
             data = _sanitize_data(
                 data, schema, on_bad_vectors=on_bad_vectors, fill_value=fill_value