Better documentation for callback function

nilmtools/filter.py

@@ -133,6 +133,34 @@ def process_numpy_interval(interval, extractor, inserter, warn_rows,
                 # we'll not miss any data when we run again later.
                 insert_ctx.update_end(old_array[processed][0])
 
+def example_callback_function(data, interval, args, insert_func, final):
+    """Example of the signature for the function that gets passed
+    to process_numpy_interval.
+
+    'data': array of data to process -- may be empty
+
+    'interval': overall interval we're processing (but not necessarily
+    the interval of this particular chunk of data)
+
+    'args': opaque arguments passed to process_numpy
+
+    'insert_func': function to call in order to insert array of data.
+    Should be passed a 2-dimensional array of data to insert.
+    Data timestamps must be within the provided interval.
+
+    'final': True if this is the last bit of data for this
+    contiguous interval, False otherwise.
+
+    Return value of 'function' is the number of data rows processed.
+    Unprocessed data will be provided again in a subsequent call
+    (unless 'final' is True).
+
+    If unprocessed data remains after 'final' is True, the interval
+    being inserted will be ended at the timestamp of the first
+    unprocessed data point.
+    """
+    raise NotImplementedError("example_callback_function does nothing")
+
 class Filter(object):
 
     def __init__(self, parser_description = None):
@@ -329,30 +357,10 @@ class Filter(object):
         If 'intervals' is not None, process those intervals instead of
         the default list.
 
-        'function' should be defined as:
-        # def function(data, interval, args, insert_func, final)
-
-        'data': array of data to process -- may be empty
-
-        'interval': overall interval we're processing (but not necessarily
-        the interval of this particular chunk of data)
-
-        'args': opaque arguments passed to process_numpy
-
-        'insert_func': function to call in order to insert array of data.
-        Should be passed a 2-dimensional array of data to insert.
-        Data timestamps must be within the provided interval.
-
-        'final': True if this is the last bit of data for this
-        contiguous interval, False otherwise.
-
-        Return value of 'function' is the number of data rows processed.
-        Unprocessed data will be provided again in a subsequent call
-        (unless 'final' is True).
-
-        If unprocessed data remains after 'final' is True, the interval
-        being inserted will be ended at the timestamp of the first
-        unprocessed data point.
+        'function' should be defined with the same interface as
+        nilmtools.filter.example_callback_function.  See the
+        documentation of that for details.  'args' are passed to
+        'function'.
         """
         extractor = NumpyClient(self.src.url).stream_extract_numpy
         inserter = NumpyClient(self.dest.url).stream_insert_numpy_context