Pandas_DataReader Error Message. The code that generated the error message is at the bottom

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TypeError                                 Traceback (most recent call last)
Cell In[5], line 5
      2 pf_data = pd.DataFrame()
      4 for a in assets:
----> 5     temp_data = wb.DataReader(a, data_source='yahoo', start='2010-01-01')
      6     pf_data[a] = temp_data['Adj Close']

File ~\anaconda3\Anaconda23\lib\site-packages\pandas\util\_decorators.py:211, in deprecate_kwarg.<locals>._deprecate_kwarg.<locals>.wrapper(*args, **kwargs)
    209     else:
    210         kwargs[new_arg_name] = new_arg_value
--> 211 return func(*args, **kwargs)

File ~\anaconda3\Anaconda23\lib\site-packages\pandas_datareader\data.py:379, in DataReader(name, data_source, start, end, retry_count, pause, session, api_key)
    367     raise NotImplementedError(msg)
    369 if data_source == "yahoo":
    370     return YahooDailyReader(
    371         symbols=name,
    372         start=start,
    373         end=end,
    374         adjust_price=False,
    375         chunksize=25,
    376         retry_count=retry_count,
    377         pause=pause,
    378         session=session,
--> 379     ).read()
    381 elif data_source == "iex":
    382     return IEXDailyReader(
    383         symbols=name,
    384         start=start,
   (...)
    390         session=session,
    391     ).read()

File ~\anaconda3\Anaconda23\lib\site-packages\pandas_datareader\base.py:253, in _DailyBaseReader.read(self)
    251 # If a single symbol, (e.g., 'GOOG')
    252 if isinstance(self.symbols, (string_types, int)):
--> 253     df = self._read_one_data(self.url, params=self._get_params(self.symbols))
    254 # Or multiple symbols, (e.g., ['GOOG', 'AAPL', 'MSFT'])
    255 elif isinstance(self.symbols, DataFrame):

File ~\anaconda3\Anaconda23\lib\site-packages\pandas_datareader\yahoo\daily.py:153, in YahooDailyReader._read_one_data(self, url, params)
    151 try:
    152     j = json.loads(re.search(ptrn, resp.text, re.DOTALL).group(1))
--> 153     data = j["context"]["dispatcher"]["stores"]["HistoricalPriceStore"]
    154 except KeyError:
    155     msg = "No data fetched for symbol {} using {}"

TypeError: string indices must be integers

assets = ['PG' , '^GSPC']
pf_data = pd.DataFrame()

for a in assets:
    temp_data = wb.DataReader(a, data_source='yahoo', start='2010-01-01')
    pf_data[a] = temp_data['Adj Close']