title: Received "ValueError: If using all scalar values, you must pass an index" in Python
body: <p>I have run the following code on python in order to retrieve various crypto currency closing prices from their inception. I have run it successfully using the following tickers:</p>
  
  <pre><code>tickers = ['USDT_BTC','USDT_BCH','USDT_ETC','USDT_XMR','USDT_ETH','USDT_DASH',
   'USDT_XRP','USDT_LTC','USDT_NXT','USDT_STR','USDT_REP','USDT_ZEC']
  </code></pre>
  
  <p>I now have changed it as follows (full code included) and get a ValueError.</p>
  
  <p>[LN1]</p>
  
  <pre><code> def CryptoDataCSV(symbol, frequency):
  
          #Params: String symbol, int frequency = 300,900,1800,7200,14400,86400
  
          #Returns: df from first available date
  
          url ='https://poloniex.com/public?command=returnChartData&amp;currencyPair='+symbol+'&amp;end=9999999999&amp;period='+str(frequency)+'&amp;start=0'
  
          df = pd.read_json(url)
  
          df.set_index('date',inplace=True)
  
          df.to_csv(symbol + '.csv')
  
          print('Processed: ' + symbol)
  </code></pre>
  
  <p>[LN2]</p>
  
  <pre><code>import pandas as pd
  import matplotlib.pyplot as plt
  %matplotlib inline
  </code></pre>
  
  <p>[LN3]</p>
  
  <pre><code>    tickers = 'ETH_BTC','STR_BTC','XMR_BTC','XRP_BTC','LTC_BTC','DASH_BTC',
  'ETC_BTC','POT_BTC','OMG_BTC','FCT_BTC','ZEC_BTC','BTS_BTC','VTC_BTC',
  'XEM_BTC','MAID_BTC','DGB_BTC','STRAT_BTC','LSK_BTC','XVC_BTC','SC_BTC',
  'DOGE_BTC','XBC_BTC','GNT_BTC','EMC2_BTC','CLAM_BTC','RIC_BTC','SYS_BTC',
  'DCR_BTC','STEEM_BTC','ZRX_BTC','GAME_BTC','VIA_BTC','NXC_BTC','NXT_BTC'
  ,'VRC_BTC','NAV_BTC','PINK_BTC','STORJ_BTC','ARDR_BTC','BCN_BTC','CVC_BTC',
  'EXP_BTC','LBC_BTC','GNO_BTC','GAS_BTC','OMNI_BTC','XCP_BTC','NEOS_BTC',
  'BURST_BTC','AMP_BTC','FLDC_BTC','FLO_BTC','SBD_BTC','BLK_BTC','BTCD_BTC',
  'NOTE_BTC','GRC_BTC','PPC_BTC','BTM_BTC','XPM_BTC','NMC_BTC','PASC_BTC',
  'NAUT_BTC','BELA_BTC','SJCX_BTC','HUC_BTC','RADS_BTC']
  </code></pre>
  
  <p>[LN4]</p>
  
  <pre><code>for ticker in tickers:
          CryptoDataCSV(ticker, 86400)
  </code></pre>
  
  <blockquote>
    <p>I now get the following error:</p>
    
    <p>--------------------------------------------------------------------------- ValueError                                Traceback (most recent call
    last)  in ()
          1 for ticker in tickers:
    ----> 2     CryptoDataCSV(ticker, 86400)</p>
    
    <p> in CryptoDataCSV(symbol, frequency)
          7     url ='<a href="https://poloniex.com/public?command=returnChartData&amp;currencyPair=" rel="nofollow noreferrer">https://poloniex.com/public?command=returnChartData&amp;currencyPair=</a>'+symbol+'&amp;end=9999999999&amp;period='+str(frequency)+'&amp;start=0'
          8 
    ----> 9     df = pd.read_json(url)
         10 
         11     df.set_index('date',inplace=True)</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\io\json\json.py in
    read_json(path_or_buf, orient, typ, dtype, convert_axes,
    convert_dates, keep_default_dates, numpy, precise_float, date_unit,
    encoding, lines)
        352         obj = FrameParser(json, orient, dtype, convert_axes, convert_dates,
        353                           keep_default_dates, numpy, precise_float,
    --> 354                           date_unit).parse()
        355 
        356     if typ == 'series' or obj is None:</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\io\json\json.py in parse(self)
        420 
        421         else:
    --> 422             self._parse_no_numpy()
        423 
        424         if self.obj is None:</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\io\json\json.py in
    _parse_no_numpy(self)
        637         if orient == "columns":
        638             self.obj = DataFrame(
    --> 639                 loads(json, precise_float=self.precise_float), dtype=None)
        640         elif orient == "split":
        641             decoded = dict((str(k), v)</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\core\frame.py in <strong>init</strong>(self,
    data, index, columns, dtype, copy)
        273                                  dtype=dtype, copy=copy)
        274         elif isinstance(data, dict):
    --> 275             mgr = self._init_dict(data, index, columns, dtype=dtype)
        276         elif isinstance(data, ma.MaskedArray):
        277             import numpy.ma.mrecords as mrecords</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\core\frame.py in _init_dict(self,
    data, index, columns, dtype)
        409             arrays = [data[k] for k in keys]
        410 
    --> 411         return _arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
        412 
        413     def _init_ndarray(self, values, index, columns, dtype=None, copy=False):</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\core\frame.py in
    _arrays_to_mgr(arrays, arr_names, index, columns, dtype)    5494     # figure out the index, if necessary    5495     if index is None:
    -> 5496         index = extract_index(arrays)    5497     else:    5498         index = _ensure_index(index)</p>
    
    <p>~\Anaconda3\lib\site-packages\pandas\core\frame.py in
    extract_index(data)    5533     5534         if not indexes and not
    raw_lengths:
    -> 5535             raise ValueError('If using all scalar values, you must pass'    5536                              ' an index')    5537 </p>
    
    <p>ValueError: If using all scalar values, you must pass an index</p>
  </blockquote>