code: def get_symbol_returns_from_yahoo(symbol, start=None, end=None):
      
  
      try:
          px = web.get_data_yahoo(symbol, start=start, end=end)
          px['date'] = pd.to_datetime(px['date'])
          px.set_index('date', drop=False, inplace=True)
          rets = px[['adjclose']].pct_change().dropna()
      except Exception as e:
          warnings.warn(
              'Yahoo Finance read failed: {}, falling back to Google'.format(e),
              UserWarning)
          px = web.get_data_google(symbol, start=start, end=end)
          rets = px[['Close']].pct_change().dropna()
  
      rets.index = rets.index.tz_localize("UTC")
      rets.columns = [symbol]
      return rets
docs: Wrapper for pandas.io.data.get_data_yahoo().
      Retrieves prices for symbol from yahoo and computes returns
      based on adjusted closing prices.
  
      Parameters
      ----------
      symbol : str
          Symbol name to load, e.g. 'SPY'
      start : pandas.Timestamp compatible, optional
          Start date of time period to retrieve
      end : pandas.Timestamp compatible, optional
          End date of time period to retrieve
  
      Returns
      -------
      pandas.DataFrame
          Returns of symbol in requested period.