Update app.py

app.py

@@ -10,6 +10,7 @@ def pd_bar():
 def plt_line():
     df = pd.DataFrame({'课程':['yw', 'sx', 'yy'], '成绩':[66, 98, 100]})
     plt.plot(df['成绩'],color='green',linestyle='dashed',marker='o',markerfacecolor='blue',markersize=20)
+    plt.close('all')
     return plt.gcf()
 demo=gr.Blocks()
 with demo: