title: How to sort the Values in Pandas Pivot table?
body: <p>I have a pandas pivot_table and want to sort the 'Price'. How can I do that?</p>
  
  <p>I tried to use sort_values but it returned ValueError.</p>
  
  <pre><code>df= pd.DataFrame({'ProductID':[78236,23658,12596,56302,48726,89235,86312,78541,10239,55563], 'Category':['Food','Food','Food','Food','Food','Food','Food','Food','Food','Food'], 'Price':[12,21,20,85,69,36,33,10,58,4]})
  pivot = df.pivot_table(index=['ProductID'],columns=['Category'],values=['Price'],aggfunc='sum')
  pivot.sort_values('Price', ascending=False)
  </code></pre>
  
  <p>I want to sort the 'Price' by descending order, but the error is:
  ValueError: The column label 'Price' is not unique.
  For a multi-index, the label must be a tuple with elements corresponding to each level.</p>
  
  <p>Can anyone tell me how fix the code? Thanks a lot.</p>
  
  <p>The expected output is:
  <a href="https://i.stack.imgur.com/iTmY1.png" rel="nofollow noreferrer">Output</a></p>