truncating a file from the top down

[rbt]

Mike Rovner wrote:
> Right. Thanks for the correction.
> 
> Fredrik Lundh wrote:
> 
>> Mike Rovner wrote:
>>
>>
>>> if os.stat says the_file is too big:
>>>  fh = open(the_file, 'rb')
>>>  fh.seek(2008, 2)
>>
>>
>>
>> should be
>>
>>     fh.seek(-2008, 2)
>>
>> right?
>>
>>
>>>  data = fh.read()
>>>  fh.close()
>>>  assert len(data)==2008 # you may want some error processing here
>>>  fh = open(the_file, 'wb')
>>>  fh.write(data)
>>>  fh.close()
>>
>>
>>
>> or
>>
>>     if os.path.getsize(the_file) > TOO_BIG:
>>         fh = open(the_file, 'rb+')
>>         fh.seek(-2008, 2)
>>         data = fh.read()
>>         fh.seek(0) # rewind
>>         fh.write(data)
>>         fh.truncate()
>>         fh.close()
>>
>> </F>
>>
>>
> 

Thanks for the info guys!