Python tell() behaving differently regarding position in the current file
<p>In the book - Core Python Programming, there is following example - </p>

<pre>
>>> f = open('/tmp/x', 'w+')
>>> f.tell()
0
>>> f.write('test line 1\n')  # add 12-char string [0-11]
>>> f.tell()
12
>>> f.write('test line 2\n')  # add 12-char string [12-23]
>>> f.tell()                  # tell us current file location (end))
24
</pre>

<p>When I run the same code in my interpreter, I get 13L in place of 12 and 26L in place of 24. 
I am running python 2.5 on Windows. </p>

<p>Has anything changed regarding behaviour or tell() in versions? How does tell decide the position in the file.</p>

<p>Thanks and Regards</p>
