示例代码：

import yfinance as yf
mmm = yf.Ticker('MMM')
mmm.history()

报错信息：

JSONDecodeError                           Traceback (most recent call last)
<ipython-input-6-68e978705cca> in <module>
      1 mmm = yf.Ticker('MMM')
----> 2 mmm.history()
~/opt/anaconda3/lib/python3.8/site-packages/yfinance/base.py in history(self, period, interval, start, end, prepost, actions, auto_adjust, back_adjust, proxy, rounding, tz, **kwargs)
    155                                "Our engineers are working quickly to resolve "
    156                                "the issue. Thank you for your patience.")
--> 157         data = data.json()
    158 
    159         # Work with errors
~/opt/anaconda3/lib/python3.8/site-packages/requests/models.py in json(self, **kwargs)
    896                     # used.
    897                     pass
--> 898         return complexjson.loads(self.text, **kwargs)
    899 
    900     @property
~/opt/anaconda3/lib/python3.8/json/__init__.py in loads(s, cls, object_hook, parse_float, parse_int, parse_constant, object_pairs_hook, **kw)
    355             parse_int is None and parse_float is None and
    356             parse_constant is None and object_pairs_hook is None and not kw):
--> 357         return _default_decoder.decode(s)
    358     if cls is None:
    359         cls = JSONDecoder
~/opt/anaconda3/lib/python3.8/json/decoder.py in decode(self, s, _w)
    335 
    336         """
--> 337         obj, end = self.raw_decode(s, idx=_w(s, 0).end())
    338         end = _w(s, end).end()
    339         if end != len(s):
~/opt/anaconda3/lib/python3.8/json/decoder.py in raw_decode(self, s, idx)
    353             obj, end = self.scan_once(s, idx)
    354         except StopIteration as err:
--> 355             raise JSONDecodeError("Expecting value", s, err.value) from None
    356         return obj, end
JSONDecodeError: Expecting value: line 1 column 1 (char 0)

解决方法：

pip install yfinance --upgrade --no-cache-dir

或者

pip uninstall yfinance
pip uninstall pandas-datareader
pip install yfinance --upgrade --no-cache-dir
pip install pandas-datareader

或者

也可以尝试yahoo_fin，使用起来很简单，维护也更好。

例如，

from yahoo_fin.stock_info import *
df = get_data('BYND', start_date='2020-08-14')