title: average of dataframe rows based on condition
body: <pre><code>data = {'a': [1, -1, -1, 1, -1, 1, -1, 1],
                  'b': [-2, 2, -2,2, -2, 2, 2,-2],
                  'c': [-1, 1, -1,-1, -1, 1,-1,1],
                  'Price': [138, 186, 124, 200,4, 6,5, 5]}
  df1 = pd.DataFrame(data)
  print(df1)
  </code></pre>
  <p>I have a huge dataset of 5000 rows like this. I would like to find the average of rows having (a,b,c), (-a,b,-c), (-a,-b,-c), (a,-b,c). Those are considered equivalent rows and I want the average price of them The output should be in this form: <a href="https://i.stack.imgur.com/XbKyK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XbKyK.png" alt="enter image description here" /></a></p>