python files run fine when executed from different directory
<p>I have a very wierd problem.
When i run the file from a different directory it runs fine.
but other wise i get this error</p>

<pre><code> from textprocessor import *
File "/home/mohit/Documents/analysis/categorization/textprocessor.py", line 2, in &lt;module&gt;
  import nltk
File "/usr/local/lib/python2.7/dist-packages/nltk/__init__.py", line 101, in &lt;module&gt;
 import ccg
File "/usr/local/lib/python2.7/dist-packages/nltk/ccg/__init__.py", line 15, in &lt;module&gt;
   from chart import *
File "/usr/local/lib/python2.7/dist-packages/nltk/ccg/chart.py", line 33, in &lt;module&gt;
from nltk.parse.api import *
File "/usr/local/lib/python2.7/dist-packages/nltk/parse/__init__.py", line 46, in &lt;module&gt;
from featurechart import *
 File "/usr/local/lib/python2.7/dist-packages/nltk/parse/featurechart.py", line 24, in &lt;module&gt;
import nltk.data
 File "/usr/local/lib/python2.7/dist-packages/nltk/data.py", line 41, in &lt;module&gt;
import zipfile
File "/usr/lib/python2.7/zipfile.py", line 460, in &lt;module&gt;
class ZipExtFile(io.BufferedIOBase):
AttributeError: 'module' object has no attribute 'BufferedIOBase'
</code></pre>

<p>I am tryin to import nltk module </p>
