title: Data Scraping: appending data doesn't work
body: <p>I have an Excel file (Compay, Start_Date, End_Date) from which I want to read the components and find the stock data available from the NSE website and save that data to a CSV file.</p>
  
  <p>So I am trying this code:</p>
  
  <pre><code>cf = pd.read_csv('Company.csv')
  cf['START_DT']=pd.to_datetime(cf['START_DT'])
  cf['END_DT']=pd.to_datetime(cf['END_DT'])
  cf
  
  OUTPUT - 
      COMPANY START_DT    END_DT
  0   SBIN    2014-01-01  2018-01-01
  1   PNB     2014-01-01  2018-01-01
  2   INFY    2014-01-01  2018-01-01
  
  for index,row in cf.iterrows():
      start_dt=row['START_DT']
      end_dt=row['END_DT']
      data = get_history(symbol=row['COMPANY'], start=start_dt, end=end_dt)
      print(data)
  data.to_csv('data.csv', sep=',')
  </code></pre>
  
  <p>Howevery, the data stored is only the data of the last company. I have tried to append the data using a dataframe but it does not work neither. </p>
  
  <p>How can I fix this?</p>