DOC: Fixed PySpark docstrings and changed some public function to private.

ci/azure/linux.yml

@@ -74,7 +74,7 @@ jobs:
       displayName: 'Lint'
 
     # TODO: change match-dir when docstrings are fixed for other backends
-    - bash: docker-compose run ibis pydocstyle --match-dir="(ibis|omniscidb)"
+    - bash: docker-compose run ibis pydocstyle -v --match-dir="(ibis|omniscidb|pyspark)"
       displayName: "Docstring check"
 
     - bash: docker-compose run ibis black --check .

ibis/pyspark/__init__.py

@@ -0,0 +1 @@
+"""PySpark backend."""

ibis/pyspark/api.py

@@ -1,12 +1,23 @@
+"""PySpark backend API module."""
 from ibis.pyspark.client import PySparkClient
 from ibis.pyspark.compiler import dialect  # noqa: F401
 
 
 def connect(session):
     """
-    Create a `SparkClient` for use with Ibis. Pipes **kwargs into SparkClient,
-    which pipes them into SparkContext. See documentation for SparkContext:
+    Create a `SparkClient` for use with Ibis.
+
+    Pipes **kwargs into SparkClient, which pipes them into SparkContext.
+    See documentation for SparkContext:
     https://spark.apache.org/docs/latest/api/python/_modules/pyspark/context.html#SparkContext
+
+    Parameters
+    ----------
+    session
+
+    Returns
+    -------
+    client : PySparkClient
     """
     client = PySparkClient(session)
 

ibis/pyspark/client.py

@@ -1,3 +1,4 @@
+"""PySpark backend client module."""
 from pyspark.sql.column import Column
 
 import ibis.common.exceptions as com
@@ -8,9 +9,7 @@
 
 
 class PySparkClient(SparkClient):
-    """
-    An ibis client that uses PySpark SQL Dataframe
-    """
+    """An ibis client that uses PySpark SQL Dataframe."""
 
     dialect = PySparkDialect
     table_class = PySparkTable
@@ -20,9 +19,7 @@ def __init__(self, session):
         self.translator = PySparkExprTranslator()
 
     def compile(self, expr, params=None, *args, **kwargs):
-        """Compile an ibis expression to a PySpark DataFrame object
-        """
-
+        """Compile an ibis expression to a PySpark DataFrame object."""
         # Insert params in scope
         if params is None:
             scope = {}
@@ -33,6 +30,7 @@ def compile(self, expr, params=None, *args, **kwargs):
         return self.translator.translate(expr, scope=scope)
 
     def execute(self, expr, params=None, limit='default', **kwargs):
+        """Execute given expression using PySpark."""
         if isinstance(expr, types.TableExpr):
             return self.compile(expr, params, **kwargs).toPandas()
         elif isinstance(expr, types.ColumnExpr):