title: How can I insert the value of filename in a new column in python dataframe?
body: <p>I need to combine multiple csv files, while combining I want to add the file name of each csv files into a column. </p>
  
  <p>I am trying using glob or pandas, but it seems not working. </p>
  
  <pre class="lang-py prettyprint-override"><code>files = glob.glob('fp')
      print (files)
      x1 = pd.concat([pd.read_csv('fp').assign(New=os.path.basename('fp')) for 'fp' in files])
  </code></pre>