title: How do I rename a blank column name in pandas df?
body: <p>I am using pandas_datareader to return stock prices. The document states that a pandas data frame is returned by the pandas_datareader. The issue is that the data frame is returned with a blank column name. That means until I rename the column I (believe this to be true) cannot add another column. Anyway here is my code:</p>
  
  <pre><code>from datetime import datetime, timedelta
  from pandas import pandas as pd
  from pandas_datareader import data, wb
  from matplotlib.figure import Figure
  from matplotlib.dates import DateFormatter
  import matplotlib.pyplot as plt
  from matplotlib import style
  import datetime as dt 
  import numpy as np
  
  style.use('ggplot')
  today = dt.date.today()
  dtStart = (dt.datetime.strptime("2017-01-01", '%Y-%m-%d'))
  dtEnd = (dt.datetime(today.year,today.month,today.day)).isoformat(' ') 
  
  def genGraph(graph_filename):
  
      dtStart = (dt.datetime.strptime("2015-01-01", '%Y-%m-%d'))
      my_stocks = {'VOD.L'} # Single sumbol.
      # my_stocks = {'VOD.L', {'BP.L'}} # Test multiple symbols.
  
      main_df = pd.DataFrame()
      df = pd.DataFrame()
  
      for sym in my_stocks:
  
          if main_df.empty:
              main_df = (data.get_data_google(sym, dtStart)['Close'])
              main_df.rename(columns = {'' : 'X'}, inplace=True)
  
              print(main_df.head())
  
          else:
              main_df = main_df.join((data.get_data_google(sym, dtStart)['Close']), how='outer')
              print(main_df)
      else:
          print('')    
      print(main_df.tail())
      return True
  genGraph('OK')
  </code></pre>
  
  <p>This currently returns:
  <a href="https://i.stack.imgur.com/roT5S.png" rel="nofollow noreferrer">One Symbol</a></p>
  
  <p><a href="https://i.stack.imgur.com/GiyRT.png" rel="nofollow noreferrer">Two Symbols</a></p>
  
  <p>I have tried various things however it seems that the column with the prices cannot be renamed. I have also tried renaming the date column and making that as an index. No luck! I wonder if it's better to stick the data into a table and then get it back. Pandas data frame seems to be overly complicated for simple operations.</p>
  
  <p>I have python 3.5.3 and the latest pandas.</p>