擅长:python、mysql、java
<pre><code>Illustration, issue reproduction.
>>> import re, sys, pprint, os
>>>
>>>
>>> def getTxtFiles():
... # Create a list of all the .txt files to be searched
... files = []
... for i in os.listdir(os.path.expanduser('~/Documents')):
... if i.endswith('.txt'):
... files.append(i)
...
>>> files = getTxtFiles()
>>> print(files)
None
>>>
>>> for i in files:
... print 'something'
...
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object is not iterable
>>>
</code></pre>
<p>修复方法是从getTxtFiles()返回文件。在</p>
^{pr2}$