typing and pre-commit fixes

src/dask_nested/backends.py

@@ -13,20 +13,21 @@
 
 
 @make_meta_dispatch.register(npd.NestedFrame)
-def make_meta_frame(x, index=None):
-    # Create an empty NestedFrame to use as Dask's underlying object meta.
+def make_meta_frame(x, index=None) -> npd.NestedFrame:
+    """Create an empty NestedFrame to use as Dask's underlying object meta."""
     result = x.head(0)
     return result
 
 
 @meta_nonempty.register(npd.NestedFrame)
-def _nonempty_nestedframe(x, index=None):
-    # Construct a new NestedFrame with the same underlying data.
+def _nonempty_nestedframe(x, index=None) -> npd.NestedFrame:
+    """Construct a new NestedFrame with the same underlying data."""
     df = meta_nonempty_dataframe(x)
     return npd.NestedFrame(df)
 
 
 @make_array_nonempty.register(npd.NestedDtype)
-def _(dtype):
+def _(dtype) -> NestedExtensionArray:
+    """Register a valid dtype for the NestedExtensionArray"""
     # must be two values
     return NestedExtensionArray._from_sequence([pd.NA, pd.NA], dtype=dtype)

src/dask_nested/io.py

@@ -22,7 +22,7 @@ def read_parquet(
     parquet_file_extension=(".parq", ".parquet", ".pq"),
     filesystem=None,
     **kwargs,
-):
+) -> NestedFrame:
     """
     Read a Parquet file into a Dask DataFrame
 
@@ -181,6 +181,7 @@ def read_parquet(
         It may be necessary to change this argument if the data files in your
         parquet dataset do not end in ".parq", ".parquet", or ".pq".
     filesystem: "fsspec", "arrow", or fsspec.AbstractFileSystem backend to use.
+        Specifies the backend to use
     dataset: dict, default None
         Dictionary of options to use when creating a ``pyarrow.dataset.Dataset`` object.
         These options may include a "filesystem" key to configure the desired