[data_loaders] Added missing doc and fixed doc related warnings

Also fixed import warnings

beat/backend/python/data_loaders.py

@@ -25,28 +25,30 @@
 #                                                                             #
 ###############################################################################
 
+"""
+============
+data_loaders
+============
 
-import time
-import logging
-logger = logging.getLogger(__name__)
-
-from functools import reduce
+This module implements all the data communication related classes
+"""
 
+import logging
 import six
-import zmq
 
 from .data import mixDataIndices
 
+logger = logging.getLogger(__name__)
 
-#----------------------------------------------------------
+# ----------------------------------------------------------
 
 
 class DataView(object):
     """Provides access to a subset of data from a group of inputs synchronized
     together
 
-    Data views are created from a data loader (see :py:class:`DataLoader`), which are
-    provided to the algorithms of types 'sequential' and 'autonomous'
+    Data views are created from a data loader (see :py:class:`DataLoader`),
+    which are provided to the algorithms of types 'sequential' and 'autonomous'
     (see :py:class:`DataLoaderList`).
 
     Example:
@@ -109,6 +111,18 @@ class DataView(object):
 
 
     def count(self, input_name=None):
+        """Returns the number of available data indexes for the given input
+        name. If none given the number of available data units.
+
+        Parameters:
+
+            input_name (str): Name of the input for which the count is
+                requested
+
+        Returns:
+            (int): Number of data indexes for the input given or the number of
+                data units.
+        """
         if input_name is not None:
             try:
                 return len(self.infos[input_name]['data_indices'])
@@ -139,7 +153,7 @@ class DataView(object):
         return (result, indices[0], indices[1])
 
 
-#----------------------------------------------------------
+# ----------------------------------------------------------
 
 
 class DataLoader(object):
@@ -205,10 +219,25 @@ class DataLoader(object):
 
 
     def input_names(self):
+        """Returns the name of all inputs associated to this data loader"""
+
         return self.infos.keys()
 
 
     def count(self, input_name=None):
+        """Returns the number of available data indexes for the given input
+        name. If none given the number of available data units.
+
+        Parameters:
+
+            input_name (str): Name of the input for which the count is
+                requested
+
+        Returns:
+            (int): Number of data indexes for the input given or the number of
+                data units.
+        """
+
         if input_name is not None:
             try:
                 return len(self.infos[input_name]['data_indices'])
@@ -219,6 +248,17 @@ class DataLoader(object):
 
 
     def view(self, input_name, index):
+        """ Returns the view associated with this data loader
+
+        Parameters:
+            input_name (str): Name of the input to get data from
+
+            index (int): Position of the data indexes to retrieve
+
+        Returns:
+            (:py:class:`DataView`) either a DataView matching the query or None
+        """
+
         if index < 0:
             return None
 
@@ -254,7 +294,7 @@ class DataLoader(object):
         return (result, indices[0], indices[1])
 
 
-#----------------------------------------------------------
+# ----------------------------------------------------------
 
 
 class DataLoaderList(object):
@@ -341,6 +381,8 @@ class DataLoaderList(object):
 
 
     def loaderOf(self, input_name):
+        """Returns the data loader matching the input name"""
+
         try:
             return [ k for k in self._loaders if input_name in k.input_names() ][0]
         except:
@@ -348,6 +390,8 @@ class DataLoaderList(object):
 
 
     def secondaries(self):
+        """Returns a list of all data loaders except the main one"""
+
         secondaries_list = DataLoaderList()
         for data_loader in self._loaders:
             if data_loader is not self.main_loader: