title: Pandas for loop over dataframe gives too many values to unpack
body: <p>I don't see why this code isn't working? I am trying to iterate over a data frame, which in this case only has one row in a for loop? There are only two columns and I have two for loop variables to take them? what am I missing please?</p>
  
  <pre><code>  print("process_list =  ",process_list)
  
    for row in process_list.itertuples():
         print("row = ", row)
  
  
    df_to_date = pd.DataFrame()
  
    try:
          print("process_list = {}  and it's type {}  process_list.itertuples() {} ".format(process_list, type(process_list),process_list.itertuples() ) )
  
          for   file_date , file_name  in process_list.itertuples(): # a whole batch of days 
                 file_to_process = dev_env + file_name
                 print("PROCESSING BATCH: ",file_to_process)
                 df  = pd.read_csv(file_to_process, header=None,skiprows=22, sep=',', comment='*', converters = {"Days" : just_number,"Percentile" : just_number,"Date" : just_number} ,names = column_names )
                 df.insert(0,'File_date',file_date)
                 df_to_date = df_to_date.append(df)
  
    except Exception as e: 
             print ("nothing to process exception = ",e)
             sys.exit(0)
  </code></pre>
  
  <p>when I run it I get </p>
  
  <pre><code>process_list =       File_date          File_name
  94   20180507  mcmhv20180507.csv
  row =  Pandas(Index=94, File_date=20180507, File_name='mcmhv20180507.csv')
  process_list =     File_date          File_name
  94   20180507  mcmhv20180507.csv  and it's type &lt;class 'pandas.core.frame.DataFrame'&gt;  process_list.itertuples() &lt;map object at 0x7f6339371e48&gt; 
  nothing to process exception =  too many values to unpack (expected 2)
  </code></pre>