Update app.py

app.py

@@ -9,7 +9,7 @@ def pd_bar():
     return ax.get_figure()
 def pd_line():
     df = pd.DataFrame({'kc':['yw', 'sx', 'yy'], 'cj':[66, 98, 78]})
-    ax = plt.plot(df['cj'])
+    plt.plot(df['cj'])
     return plt
 demo=gr.Blocks()
 with demo: