title: How to get a BarContainer Object from an AxesSubplot object in matplotllib?
body: <p>I'm fairly new with matplotlib, but as I understand: </p>
  
  <pre><code>fig,ax = plt.subplot()
  ax.bar(x,y) 
  </code></pre>
  
  <h1>or</h1>
  
  <pre><code>bar = ax.bar(x,y)
  </code></pre>
  
  <p>returns a BarContainer type object. From this we can <code>bar.axes</code> to get the axes ax on which this is plotted. </p>
  
  <p>but what if we have an axes <code>ax</code> and we didn't explicitly store the barplot in a <code>bar</code> object. 
  Now we go ahead and do a whole lot of changes on the axes <code>ax</code>, as in <code>ax.position ax.legend</code> etc etc.
  Now we have an <code>AxesSubplot</code> type object <code>ax</code>....from this, how can we extract our <code>BarContainer</code> type object?</p>
  
  <p>I have a function that accepts the subscriptable <code>BarContainer</code> object, and by the end of my processing I only have an <code>AxesSubplot</code> type object... I can't figure out how to get one from the other..
  We can get artists, labels, axis etc etc from the <code>AxesSubplot</code> object but I see no way to get the <code>Container</code> type object from it. Please assist, Thanks!</p>