title: Iterate over different dataframe
body: <p>I am trying to iterate over three data frames to find the difference between them. I have a master data frame which contains everything and two other data frames which contains partial of master data frame. I am trying to write a python code to identify what is missing in the other two files. Master file looks like following:</p>
  
  <pre><code>ID  Name
  1   Mike
  2   Dani
  3   Scott
  4   Josh
  5   Nate
  6   Sandy
  </code></pre>
  
  <p>second data frame looks like following:</p>
  
  <pre><code>ID  Name
  1   Mike
  2   Dani
  3   Scott
  6   Sandy
  </code></pre>
  
  <p>Third data frame looks like following:</p>
  
  <pre><code>ID  Name
  1   Mike
  2   Dani
  3   Scott
  4   Josh
  5   Nate
  </code></pre>
  
  <p>So there will be two output data frame. Desired output for looks like following for second data frame:</p>
  
  <pre><code>ID  Name
  4   Josh
  5   Nate
  </code></pre>
  
  <p>desired output for third data frame looks like following:</p>
  
  <pre><code>ID  Name
  6   Sandy
  </code></pre>
  
  <p>I didn't find anything similar on Google. I tried this:</p>
  
  <pre><code>for i in second['ID'], third['ID']:
     if i not in master['ID']:
       print(i)
  </code></pre>
  
  <p>It returns all the data in master file. </p>
  
  <p>Also if I try this code :</p>
  
  <pre><code>import pandas as pd
  
  names = ["Mike", "Dani", "Scott", "Josh", "Nate", "Sandy"]
  ids = [1, 2, 3, 4, 5, 6]
  master = pd.DataFrame({"ID": ids, "Name": names})
  # print(master)
  
  names_second = ["Mike", "Dani", "Scott", "Sandy"]
  ids_second = [1, 2, 3, 6]
  second = pd.DataFrame({"ID": ids_second, "Name": names_second})
  # print(second)
  
  names_third = ["Mike", "Dani", "Scott", "Josh", "Nate"]
  ids_third = [1, 2, 3, 4, 5]
  third = pd.DataFrame({"ID": ids_third, "Name": names_third})
  # print(third)
  for i in master['ID']:
      if i not in second["ID"]:
          print("NOT IN SECOND", i)
      if i not in third["ID"]:
          print("NOT IN THIRD", i)
  </code></pre>
  
  <p>OUTPUT :: </p>
  
  <pre><code>NOT IN SECOND 4
  NOT IN SECOND 5
  NOT IN THIRD 5
  NOT IN SECOND 6
  NOT IN THIRD 6
  </code></pre>
  
  <p>Why it says <code>NOT IN SECOND 6</code> and <code>NOT IN THIRD 5</code>?</p>
  
  <p>Any suggestion? Thanks in advance.</p>