Python的最大递归深度错误 “maximum recursion depth exceeded while calling a Python object”

上海isp

Traceback (most recent call last):　　
  File "<stdin>", line 1, in <module>
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1045, in __str__
　　
    return self.encode()
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1055, in encode
　　
    u = self.decode(indent_level, encoding, formatter)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1126, in decode
　　
    indent_contents, eventual_encoding, formatter)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1195, in decode_contents
　　
    formatter))
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1126, in decode
　　
  ......
　　

　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1126, in decode
　　
    indent_contents, eventual_encoding, formatter)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1195, in decode_contents
　　
    formatter))
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 1098, in decode
　　
    text = self.format_string(val, formatter)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 163, in format_string
　　
    output = formatter(s)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 120, in substitute_xml
　　
    ns, EntitySubstitution.substitute_xml)
　　
  File "C:\Python27\lib\site-packages\bs4\element.py", line 104, in _substitute_if_appropriate
　　
    if (isinstance(ns, NavigableString)
　　
RuntimeError: maximum recursion depth exceeded while calling a Python object