title: Obtain list of strings from column index of pandas dataframe
body: <p>First off, here is what my .xlsx timeseries data looks like:</p>
  
  <p><img src="https://i.stack.imgur.com/xn27O.png" alt="What the data looks like in excel"></p>
  
  <p>and here is how I'm reading it:</p>
  
  <pre><code>def loaddata(filepaths):
      t1 = time.clock()
      for i in range(len(filepaths)):
          xl = pd.ExcelFile(filepaths[i])
          df = xl.parse(xl.sheet_names[0], header=0, index_col=2, skiprows=[0,2,3,4], parse_dates=True)
          df = df.dropna(axis=1, how='all') 
          df = df.drop(['Decimal Year Day', 'Decimal Year Day.1', 'RECORD'], axis=1)
          df.index = pd.DatetimeIndex(((df.index.asi8/(1e9*60)).round()*1e9*60).astype(np.int64)).values
  
          if i == 0:
              dfs = df
          else:
              dfs = concat([dfs, df], axis=1)
  
      t2 = time.clock()
      print "Files loaded into dataframe in %s seconds" %(t2-t1)
  
      return dfs
  
  files = ["London Lysimeters corrected 5min.xlsx"]
  data = loaddata(files)
  </code></pre>
  
  <p>What I need to be able to do is read the column labels AND units (row 2 and 3) as well as the values into a pandas dataframe, and be able to access the labels and units row as a list of strings. I can't seem to figure out how to load up both row 2 and 3 and have the time read in correctly into pandas datetimeindex, but it works fine if I only upload the labels. Also I've looked everywhere and can't figure out how to get the column headers as a list.</p>
  
  <p>I would appreciate it if anyone could help with either of these issues.</p>