title: isin pandas dataframe from 2 other dataframe
body: <p>i have a pandas dataframe.</p>
  
  <pre><code>df = pd.DataFrame({'countries':['US','UK','Germany','China','India','Pakistan','lanka'],
                 'id':['a','b','c','d','e','f','g']})
  </code></pre>
  
  <p>also i have two more dataframes. df2 and df3.</p>
  
  <pre><code>df2 = pd.DataFrame({'countries':['Germany','China'],
                 'capital':['c','d']})
  
  df3 = pd.DataFrame({'countries':['lanka','USA'],
                 'capital':['g','a']})
  </code></pre>
  
  <p>i want to find the rows in df where df is in df2 and df3</p>
  
  <p>i had this code:</p>
  
  <pre><code>df[df.id.isin(df2.capital)]
  </code></pre>
  
  <p>but it will find the rows which is in df2.</p>
  
  <p>is there any way i can do it for both df2 and df3 in a single code.</p>
  
  <p>i'e rows from df where df is in df2 and df3</p>