擅长:python、mysql、java
<p>您将<code>fieldnames</code>参数设置为<code>None</code>;您需要确保<code>allFields</code>是一个有序的字符串序列。在</p>
<p>演示说明问题:</p>
<pre><code>>>> from cStringIO import StringIO
>>> import csv
>>> w = csv.DictWriter(StringIO(), fieldnames=None)
>>> w.writerow({'foo':'bar'})
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/opt/lib/python2.7/csv.py", line 148, in writerow
return self.writer.writerow(self._dict_to_list(rowdict))
File "/opt/lib/python2.7/csv.py", line 141, in _dict_to_list
wrong_fields = [k for k in rowdict if k not in self.fieldnames]
TypeError: argument of type 'NoneType' is not iterable
>>> w = csv.DictWriter(StringIO(), fieldnames=['foo'])
>>> w.writerow({'foo':'bar'})
</code></pre>