title: Elegant way to work with multiple dataframes in Pandas
body: <p>I have a bit of code which currently looks like this:</p>
  
  <pre><code>if os.path.isfile('D:\\df_1'):
      df_1 = pd.read_pickle('D:\\df_1')
  else:
      df_1 = pd.DataFrame(columns = ['Date', 'Location', 'Product'])
  if os.path.isfile('D:\\df_2'):
      df_2 = pd.read_pickle('D:\\df_2')
  else:
      df_2 = pd.DataFrame(columns = ['Date', 'Location', 'Product'])
  
  [...]
  
  if os.path.isfile('D:\\df_20'):
      df_20 = pd.read_pickle('D:\\df_20')
  else:
      df_20 = pd.DataFrame(columns = ['Date', 'Location', 'Product'])
  </code></pre>
  
  <p>Basically what I'm doing is checking if the Dataframe already exists, if it does load it, otherwise create an empty dataframe. I need this because then the code will try to append new data to each of the dataframe. So I will have something like:</p>
  
  <pre><code>[retrieve new data and clean it]
  df_1 = pd.concat([df_1, df_1_new_data])
  </code></pre>
  
  <p>Do this for all the 20 dataframes I have (they contain different things, so I want to keep them separate), and then save them in order to retrieve them again the day after and add new data to them:</p>
  
  <pre><code>df_1.to_pickle('D:\\df_1')
  df_2.to_pickle('D:\\df_2')
  [...]
  df_20.to_pickle('D:\\df_20')
  </code></pre>
  
  <p>Now, it's already quite heavy to do it with 20 dataframes, but I will probably need to add some more! Is there a way to read the different dataframes, and then write them to pickle in a for loop or something like this? So to reduce the lines of code for the many I have now to a simple 2 lines for loop? Thank you!</p>