Fix indent. Do not use len sequence to determine if a sequence is empty (len-as-condition).

Author: jbampton

plotly/offline/offline.py

@@ -267,8 +267,8 @@ def _plot_html(figure_or_data, config, validate, default_width,
         optional_line2 +
         '</script>'
         '').format(
-        id=plotdivid, script=script,
-        height=height, width=width)
+            id=plotdivid, script=script,
+            height=height, width=width)
 
     return plotly_html_div, plotdivid, width, height
 
@@ -369,7 +369,7 @@ def iplot(figure_or_data, show_link=True, link_text='Export to plot.ly',
         if image not in __IMAGE_FORMATS:
             raise ValueError('The image parameter must be one of the following'
                              ': {}'.format(__IMAGE_FORMATS)
-                             )
+                            )
         # if image is given, and is a valid format, we will download the image
         script = get_image_download_script('iplot').format(format=image,
                                                            width=image_width,
@@ -493,7 +493,7 @@ def plot(figure_or_data, show_link=True, link_text='Export to plot.ly',
                 if image not in __IMAGE_FORMATS:
                     raise ValueError('The image parameter must be one of the '
                                      'following: {}'.format(__IMAGE_FORMATS)
-                                     )
+                                    )
                 # if the check passes then download script is injected.
                 # write the download script:
                 script = get_image_download_script('plot')

plotly/widgets/graph_widget.py

@@ -121,7 +121,7 @@ def _handle_registration(self, event_type, callback, remove):
         self._event_handlers[event_type].register_callback(callback,
                                                            remove=remove)
         event_callbacks = self._event_handlers[event_type].callbacks
-        if (len(event_callbacks) and event_type not in self._listener_set):
+        if (event_callbacks and event_type not in self._listener_set):
             self._listener_set.add(event_type)
             message = {'task': 'listen', 'events': list(self._listener_set)}
             self._handle_outgoing_message(message)