Added a new play button widget and changed docstrings to match Pep8

Author: Aodhan Sweeney

examples/HurricaneTracker.py

@@ -6,9 +6,9 @@
 This GUI takes data pulled from the National
 Hurricane Center and efficiently sifts through
 the data to plot specific storms and their
-tracks.
-
-This code now creates the GUI
+tracks. The GUI runs using ipwidgets, and
+is intended to be used as an ipython
+notebook.
 """
 import os
 
@@ -20,8 +20,23 @@
 from siphon.simplewebservice.nhc import nhc
 
 class NHC_GUI:
+    """
+    Graphic User Interface designed to allow users to access National Hurricane Center data.
+
+    This class uses ipython widgets, and the order in which the functions appear in this script
+    correspond to the order in which the functions and widgets are called/used.
+    """
+
     def __init__(self):
-        self.NHCD = nhc.NHCD()
+        """
+        Create object that references NHC.py and thus the National Hurricane Center.
+
+        This initiation creates the National Hurricane Center object and also creates
+        a widget that allows the user to 1.) select the year in which to find storms,
+        and 2.) indicate when they have chosen the year and when to continue with parsing
+        the storm_table.
+        """
+        self.NHCD = NHC.NHCD()
         self.storm_table = self.NHCD.storm_table
         # Year Slider Widget to select year for which to retrieve storm data.
         self.year_slider = widgets.IntSlider(min=1851, max=2019, value=2019,
@@ -35,24 +50,48 @@ def __init__(self):
 
 
     def get_storms_slider(self, year_slider):
+        """
+        Take a year chosen by the user, and create a list of all storms during that year.
+
+        Parameters
+        ----------
+        year_slider: ipywidget
+            tells value of year chosen by the user
+        """
         self.year = str(year_slider)
         self.one_year_table = self.storm_table[self.storm_table.Year == str(year_slider)]
         self.storm_names = widgets.Dropdown(options=self.one_year_table['Name'],
                                             description='Storm Names: ')
         widgets.interact(self.get_name_dropdown, storm_names=self.storm_names)
 
     def get_name_dropdown(self, storm_names):
+        """
+        Take names created by previous function and allow selection of which models to plot.
+
+        Parameters
+        ----------
+        storm_names: list
+            all storms in a given year
+        """
         name = self.storm_names.value
         one_storm_row = self.one_year_table[self.one_year_table.Name == name]
         self.filename = one_storm_row.Filename
         file_name = self.filename.tolist()
         if self.filename.empty is False:
             self.filename = file_name[0]
         elif self.filename.empty is True:
-            print('No file name data for this year.')
+            raise Exception('ValueError: No file name data for this year.')
 
     def get_track(self, track_button):
-
+        """
+        Query whether track button has been toggled, and create select model widget.
+
+        Parameters
+        ----------
+        track_button: ipywidget
+            button that when toggled indicates that user is ready to select the model
+            tracks for the chosen storm.
+        """
         if self.track_button.value is True:
             unique_models = self.NHCD.get_tracks(self.year, self.filename)
             self.model_select = widgets.SelectMultiple(options=unique_models,
@@ -62,20 +101,35 @@ def get_track(self, track_button):
             widgets.interact(self.get_models, models=self.model_select)
 
     def get_models(self, models):
-        """get_models is a function that is linked to the selection widget which allows for
-        multiple models to be selected to plot for a specific hurricane track."""
-
+        """
+        Select models from a list of all models for a given stormself.
+
+        Parameters
+        ----------
+        models: list
+            list of ran for a given storm
+        """
         self.NHCD.model_selection_latlon(models)
         self.date_times = self.NHCD.date_times
         self.plot_slider = widgets.IntSlider(min=0, max=(len(self.date_times)-1),
                                                  value=0, description='Tracks Time',
                                                  disabled=False)
-        widgets.interact(self.plotting, plot_slider=self.plot_slider)
+        self.play = widgets.Play(interval=800, min=0, max=(len(self.date_times)-1),
+                                                 value=0, description='Tracks Time')
+        widgets.jslink((self.plot_slider, 'value'), (self.play, 'value'))
+        self.box = widgets.HBox([self.plot_slider, self.play])
+        display(self.plot_slider)
+        widgets.interact(self.plotting, plot_slider=self.play)
 
     def plotting(self, plot_slider):
-        """plotting is a function that that plots the models tracks and best tracks for all
-        selected models. These tracks are then plotted on the Blue Marble projection. """
-
+        """
+        Plot selected model tracks and best track for given storm.
+
+        Parameters
+        ----------
+        plot_slider: ipywidget
+            Widget where assigned value is plot/play widget value
+        """
         if self.plot_slider.disabled is False:
 
             # Identifying the time associated with the models for time text box
@@ -118,8 +172,7 @@ def plotting(self, plot_slider):
                 if len(lats) != 0:
                     model_list = model_type['Model'].tolist()
                     self.ax.plot(lons, lats, marker='o', color=next(colors),
-                                 label
-                                 =model_list[0])
+                                 label=model_list[0])
 
             plt.title('Storm Name: {0} Year: {1}'.format(self.storm_names.value,
                       str(self.year_slider.value)))