first attempt at reactive element

app.py

@@ -1,4 +1,4 @@
-from shiny import App, ui
+from shiny import App, ui, render, reactive
 from shinywidgets import output_widget, render_widget
 import fastf1 as ff1
 import matplotlib.pyplot as plt
@@ -18,10 +18,8 @@ app_ui = ui.page_fluid(
 )
 
 def server(input, output, session):
-    @output
-    @render_widget
-    def my_widget():
-
+    @reactive.Calc
+    def get_data():
         ff1.Cache.enable_cache('.\cache')
 
         session = ff1.get_session(2023, input.track, 'R')
@@ -37,7 +35,11 @@ def server(input, output, session):
         points = np.array([x, y]).T.reshape(-1, 1, 2)
         segments = np.concatenate([points[:-1], points[1:]], axis=1)
         gear = tel['nGear'].to_numpy().astype(float)
+        return lap, tel, x,y,points,segments,gear
 
+    @output
+    @render_widget
+    def my_widget(lap, tel, x,y,points,segments,gear):
         cmap = cm.get_cmap('Paired')
         lc_comp = LineCollection(segments, norm=plt.Normalize(1, cmap.N+1), cmap=cmap)
         lc_comp.set_array(gear)
@@ -48,15 +50,15 @@ def server(input, output, session):
         plt.tick_params(labelleft=False, left=False, labelbottom=False, bottom=False)
 
         title = plt.suptitle(
-            f"Fastest Lap Gear Shift Visualization\n"
-            f"{lap['Driver']} - {session.event['EventName']} {session.event.year}"
-        )
+                f"Fastest Lap Gear Shift Visualization\n"
+                f"{lap['Driver']} - {session.event['EventName']} {session.event.year}"
+                )
 
         cbar = plt.colorbar(mappable=lc_comp, label="Gear", boundaries=np.arange(1, 10))
         cbar.set_ticks(np.arange(1.5, 9.5))
         cbar.set_ticklabels(np.arange(1, 9))
-        
-        return plt
+            
+    return plt
 
 
 app = App(app_ui, server)