fix: ibis.connect always returns a backend

BREAKING CHANGE: Previously `ibis.connect` would return a `Table` object
when calling `connect` on a parquet/csv file. This now returns a backend
containing a single table created from that file. When possible users
may use `ibis.read` instead to read files into ibis tables.

ibis/backends/base/__init__.py

@@ -763,10 +763,6 @@ def connect(resource: Path | str, **kwargs: Any) -> BaseBackend:
 
     Examples
     --------
-    Connect to an on-disk parquet or csv file (uses duckdb by default):
-    >>> con = ibis.connect("/path/to/data.parquet")
-    >>> con = ibis.connect("/path/to/data.csv")
-
     Connect to an in-memory duckdb database:
     >>> con = ibis.connect("duckdb://")
 
@@ -799,7 +795,8 @@ def connect(resource: Path | str, **kwargs: Any) -> BaseBackend:
         elif path.endswith((".parquet", ".csv", ".csv.gz")):
             # Load parquet/csv/csv.gz files with duckdb by default
             con = ibis.duckdb.connect(**kwargs)
-            return con.register(path)
+            con.register(path)
+            return con
         else:
             raise ValueError(f"Don't know how to connect to {resource!r}")
 

ibis/backends/tests/test_client.py

@@ -13,7 +13,6 @@
 import ibis.common.exceptions as com
 import ibis.expr.datatypes as dt
 import ibis.expr.operations as ops
-import ibis.expr.types as ir
 from ibis.util import guid
 
 
@@ -586,8 +585,8 @@ def test_connect_sqlite(url, ext, tmp_path):
 )
 def test_connect_local_file(out_method, extension, test_employee_data_1, tmp_path):
     getattr(test_employee_data_1, out_method)(tmp_path / f"out.{extension}")
-    t = ibis.connect(tmp_path / f"out.{extension}")
-    assert isinstance(t, ir.Table)
+    con = ibis.connect(tmp_path / f"out.{extension}")
+    t = list(con.tables.values())[0]
     assert not t.head().execute().empty