Matplotlib error AttributeError: 'AxesSubplot' object has no attribute 'bar

 import numpy as np 
The import matplotlib 
X=np. Arange (len (df_0_age) # the label locations 
Width=0.35 # the width of the bars 
Labels=df_0_age [' interval '] values 
FIG, ax=PLT. Subplots () 
Rects1=ax. Bar (x - width/2, df_0_age [' proportion/ranking _ other '], width, label='other') 
Rects2=ax. Bar (x + width/2, df_0_age [' proportion/ranking _ yunnan '], width, label='yunnan') 

# Add some text for labels, the title and the custom x axis tick labels, etc. 
Ax. Set_ylabel (' proportion ') 
Ax. Set_title (' 0 ') 
Ax. Set_xticks (x) 
Ax. Set_xticklabels (labels) 
Ax. Legend () 

Ax. Bar_label (rects1, padding=3) 
Ax. Bar_label (rects2, padding=3)

I use a website with examples of this bar_label function is an error, version 3.3.4, with website didn't difference how many, should not version problem