问为什么to_csv会出错？

EN

with open('myData', 'a') as f:
    if count1 == 1:
        df.to_csv(f,index=False, quoting=3 )
    else:
        df.to_csv(f,index=False, quoting=3 , header = False)


Error: need to escape, but no escapechar set

---------------------------------------------------------------------------
Error                                     Traceback (most recent call last)
<ipython-input-22-7b964e5d0ae8> in <module>()
 27         action.perform()
 28         html = browser.page_source
---> 29         ScrapePage(html)

<ipython-input-20-1d50d699fe76> in ScrapePage(html)
 56     with open('myData', 'a') as f:
 57         if count1 == 1:
---> 58             df.to_csv(f,index=False, quoting=3 )
 59         else:
 60             df.to_csv(f,index=False, quoting=3 , header = False)

C:\Anaconda2\lib\site-packages\pandas\core\frame.pyc in to_csv(self, path_or_buf, sep,
na_rep, float_format, columns, header, index, index_label, mode, encoding, compression,
quoting, quotechar, line_terminator, chunksize, tupleize_cols, date_format, doublequote,
escapechar, decimal, **kwds)

1330                                      escapechar=escapechar,
1331                                      decimal=decimal)
-> 1332         formatter.save()
1333 
1334         if path_or_buf is None:

C:\Anaconda2\lib\site-packages\pandas\core\format.pyc in save(self)
1504 
1505             else:
-> 1506                 self._save()
1507 
1508         finally:

C:\Anaconda2\lib\site-packages\pandas\core\format.pyc in _save(self)
1604                 break
1605 
-> 1606             self._save_chunk(start_i, end_i)
1607 
1608     def _save_chunk(self, start_i, end_i):

C:\Anaconda2\lib\site-packages\pandas\core\format.pyc in _save_chunk(self, start_i, end_i)
1631                                         quoting=self.quoting)
1632 
-> 1633         lib.write_csv_rows(self.data, ix, self.nlevels, self.cols, self.writer)
1634 
1635 # from collections import namedtuple

pandas\lib.pyx in pandas.lib.write_csv_rows (pandas\lib.c:19840)()

Error: need to escape, but no escapechar set