maximum recursion error Python

Question

I am trying to scrape some box scores from ESPN.com and put them in Pandas DataFrame. I have done similar things in the past in the same manner with out any problems. However in this case I am getting this error when I try to save the DataFrame.

RuntimeError: maximum recursion depth exceeded while calling a Python object

I get a similar error when trying to save it as a hdf5 table.

Even this snippet gives the same error. I am pretty confused on why it is doing this? Is it something to do with the function?

url = 'http://espn.go.com/nba/boxscore?gameId=400278773'   
boxurl = urllib2.urlopen(url).read()
soup = BeautifulSoup(boxurl)

tables = soup.findAll('table')
lineScoreTable = tables[-2]
lineScoreRows = lineScoreTable.findAll('tr') 

def GetAwayQTRScores():
    scoreRow = lineScoreRows[1].findAll('td')
    awayQTRScores = []
    for x in scoreRow:
        scores =  x.string
        awayQTRScores.append(scores)
    return awayQTRScores  # returns list

 awayQTRScores = GetAwayQTRScores()

 awayTeam = awayQTRScores[0]
 awayQ1 = int(awayQTRScores[1])
 awayQ2 = int(awayQTRScores[2])
 awayQ3 = int(awayQTRScores[3])
 awayQ4 = int(awayQTRScores[4])
 awayOT1 = np.nan if len(awayQTRScores) < 7 else int(awayQTRScores[5])
 awayOT2 = np.nan if len(awayQTRScores) < 8 else int(awayQTRScores[6])
 awayOT3 = np.nan if len(awayQTRScores) < 9 else int(awayQTRScores[7])
 awayOT4 = np.nan if len(awayQTRScores) < 10 else int(awayQTRScores[8])



 data = {'AwayTeam' :[awayTeam],
    'AwayQ1' : [awayQ1],
    'AwayQ2' : [awayQ2],
    'AwayQ3' : [awayQ3],
    'AwayQ4' : [awayQ4],
    'AwayOT1' : [awayOT1],
    'AwayOT2' : [awayOT2],
    'AwayOT3' : [awayOT3],
    'AwayOT4' : [awayOT4]}


testScrape = pd.DataFrame(data)
testScrape.save('testScrape')

RuntimeError Traceback (most recent call last) in () ----> 1 testScrape.save('testScrape')

C:\Python27\lib\site-packages\pandas\core\generic.pyc in save(self, path) 26 27 def save(self, path): ---> 28 com.save(self, path) 29 30 @classmethod

C:\Python27\lib\site-packages\pandas\core\common.pyc in save(obj, path) 1562 f = open(path, 'wb') 1563 try: -> 1564 pickle.dump(obj, f, protocol=pickle.HIGHEST_PROTOCOL) 1565 finally: 1566 f.close()

RuntimeError: maximum recursion depth exceeded while calling a Python object

print data

returns

{'AwayTeam': [u'LAL'], 'AwayOT4': [nan], 'AwayQ4': [27], 'AwayQ3': [36], 'AwayQ2': [24], 'AwayQ1': [16], 'AwayOT1': [nan], 'AwayOT2': [nan], 'AwayOT3': [nan]}

In general, it helps to show the full traceback, or at least which line raises the exception, instead of just the text of the exception. — abarnert
I can't see any explicit recursion in your code. Could you please post the complete stack trace? — Hyperboreus
Also, please fix your indentation to make your code runnable. — abarnert
What's strange is that you can do DataFrame(testScrape.to_dict('foo')).save(), this looks like a strange bug, probably best reporting it as a github issue. — Andy Hayden
Hold on, I've got it. awayTeam isn't a str, it's a self-containing object. Let me write up an answer with more details. — abarnert

abarnert abarnert · Accepted Answer · 2013-10-22T23:00:52

This exception from pickle.dump usually means that you're trying to pickle an object that contains itself (directly or indirectly).

But what object contains itself? When you print them all out, they all look fine.

It's awayTeam This is a bs4.element.NavigableString, which you get by doing this:

awayTeam = awayQTRScores[0]

You may not notice it from just print awayTeam or even print repr(awayTeam), because NavigableString is a subclass of unicode and doesn't define a custom __str__ or __repr__, so it prints just like a string.

But it also doesn't define a custom pickler, so it uses the default pickler. In general, bs4 objects aren't designed to be pickled, and many of them can't be. In particular, NavigableString is an object that indirectly contains itself. As the docs say:

If you want to use a NavigableString outside of Beautiful Soup, you should call unicode() on it to turn it into a normal Python Unicode string. If you don’t, your string will carry around a reference to the entire Beautiful Soup parse tree, even when you’re done using Beautiful Soup.

And of course the parse tree contains a reference to the string, which etc. So, this type can never be pickled.

The solution is simple. You wanted a plain old unicode string, not a NavigableString, so you can just do this:

awayTeam = unicode(awayQTRScores[0])

maximum recursion error Python

1 Answers