overwrite bytes in file

[Neal Norwitz]

Marcus Stojek wrote:
> 
> Hi,
> how can I overwrite certain bytes in a file (Win NT) and
> keep the rest unchanged.
> All open options are truncating the file.

The mode should be 'r+'.  On windows it would probably be better
to use 'rb+'.

>>> f = open('nn')
>>> print f.read()
test

>>> f = open('nn', 'r+')
>>> f.seek(2)
>>> f.write('a')
>>> f.close()
>>> f = open('nn')
>>> print f.read()
teat

Neal