title: How I check if some attributes in the process/dataset are met or not?
body: <p>I am new in Python and want to make some data analysis :) </p>
  
  <p>I have these columns in my dataset: date, material_code, vendor and price. </p>
  
  <p>I would like to filter cases where I have for the same date and the same code and from the same vendor the different price.</p>
  
  <p>I can think of some groupby function but don't know how to start. </p>
  
  <p>Thanks for your help!</p>