title: Common elements in a dataframe column
body: <p>I have a list of CSV's , which I am currently reading in a dataframe in Pandas. I need to find the common elements in one of columns of a dataframe.</p>
  
  <pre><code> df1 = pd.read_csv("example.csv")
   df2 = pd.read_csv("example1.csv")
   val = np.intersect1d(example[' column'], example1[' column'])
  </code></pre>
  
  <p>How can I do it for multiple files.</p>