Add HDFS section to API docs

Author: wesm

python/doc/source/api.rst

@@ -164,6 +164,16 @@ Input / Output and Shared Memory
    create_memory_map
    PythonFile
 
+Filesystems
+-----------
+
+.. autosummary::
+   :toctree: generated/
+
+   hdfs.connect
+   HadoopFilesystem
+   LocalFilesystem
+
 .. _api.ipc:
 
 Interprocess Communication and Messaging

python/pyarrow/hdfs.py

@@ -126,7 +126,7 @@ def connect(host="default", port=0, user=None, kerb_ticket=None,
 
     Returns
     -------
-    client : HDFSClient
+    filesystem : HadoopFilesystem
     """
     fs = HadoopFilesystem(host=host, port=port, user=user,
                           kerb_ticket=kerb_ticket, driver=driver)