Rewrite app-express.py using Shiny Express

Author: gadenbuie

shiny/api-examples/input_action_button/app-express.py

@@ -1,26 +1,21 @@
 import matplotlib.pyplot as plt
 import numpy as np
 
-from shiny import App, Inputs, Outputs, Session, reactive, render, ui
+from shiny import reactive, render
+from shiny.express import input, ui
 
-app_ui = ui.page_fluid(
-    ui.input_slider("n", "Number of observations", min=0, max=1000, value=500),
-    ui.input_action_button("go", "Go!", class_="btn-success"),
-    ui.output_plot("plot"),
-)
 
+ui.input_slider("n", "Number of observations", min=0, max=1000, value=500)
+ui.input_action_button("go", "Go!", class_="btn-success")
 
-def server(input: Inputs, output: Outputs, session: Session):
-    @render.plot(alt="A histogram")
-    # Use reactive.event() to invalidate the plot only when the button is pressed
-    # (not when the slider is changed)
-    @reactive.event(input.go, ignore_none=False)
-    def plot():
-        np.random.seed(19680801)
-        x = 100 + 15 * np.random.randn(input.n())
-        fig, ax = plt.subplots()
-        ax.hist(x, bins=30, density=True)
-        return fig
 
-
-app = App(app_ui, server)
+@render.plot(alt="A histogram")
+# Use reactive.event() to invalidate the plot only when the button is pressed
+# (not when the slider is changed)
+@reactive.event(input.go, ignore_none=False)
+def plot():
+    np.random.seed(19680801)
+    x = 100 + 15 * np.random.randn(input.n())
+    fig, ax = plt.subplots()
+    ax.hist(x, bins=30, density=True)
+    return fig