大熊猫腌渍错误 - 超出最大递归深度

Question

I'm new to Python and its pickle format.

So I came across an error message when I wrote to_pickle.

>>> import pandas as pd
>>> old = pd.read_pickle('vol.pkl')
>>> old = old.append(updates)
>>> pd.to_pickle(old,'vol.pkl')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "\\\python-site-packages\win64_vc11\Lib\site-packages\pandas-0.13.0-py2.7-win-amd64.egg\pandas\io\pickle.py", line 15, in to_pickle
    pkl.dump(obj, f, protocol=pkl.HIGHEST_PROTOCOL)
  File "\\\python-site-packages\win64_vc11\Lib\site-packages\bs4\element.py", line 664, in __getnewargs__
    return (unicode(self),)
RuntimeError: maximum recursion depth exceeded while calling a Python object

Anyone knows why this happens and how to solve this?

Thanks.

Answer 1

I had the same problem. In my case it was caused by adding a bs4.element.NavigableString element to the dataframe. Converting that to a string solved the issue!

The comment "In the line return (unicode(self),): what is the value of the variable self?" put me to the solution, thanks! I noticed the bs4\\element.py in the error message. I realised that I was (accidently) also adding bs4 items to my dataframe. I incorrectly assumed that soup.title.string returned a string but it returned a type bs4.element.NavigableString.

    # the issue: type(title) = bs4.element.NavigableString

    ~\Anaconda3\lib\site-packages\bs4\element.py in __getnewargs__(self)
    784 
    785     def __getnewargs__(self):
--> 786         return (str(self),)
    787 
    788     def __getattr__(self, attr):

RecursionError: maximum recursion depth exceeded while getting the str of an object