Update app.py

app.py

@@ -6,7 +6,7 @@ plt.rcParams['axes.unicode_minus']=False
 def pd_bar():
     df = pd.DataFrame({'课程':['语文', '数学', '英语'], '成绩':[66, 98, 78]})
     ax = df.plot(x='课程',y='成绩',kind='bar',title='chinese word error!', color=["red","green","purple"])
-    return ax #plt
+    return ax.get_figure() #plt
 def plt_line():
     plt.close('all')
     df = pd.DataFrame({'课程':['yw', 'sx', 'yy'], '成绩':[66, 98, 100]})