clarification on open file modes

Gabriel Genellina gagsl-py at
Fri Jan 5 04:47:43 CET 2007

At Thursday 4/1/2007 23:46, tubby wrote:

>I understand that doing the following on Windows to a binary file (a
>jpeg or exe files for example) can cause file corruption, is that correct?
>fp = open(file_name, 'r')
>How can a simple open in read mode corrupt data???

You can't corrupt *that* file if you only open it. But if you *read* 
it and process the input data, you'll get some garbage. And if you 
write such data (to the same file or another one), it will be corrupted.
Using "rb" or "wb" for binary files won't do any harm on systems 
where it doesn't matter, and it's the right way on systems where it does.

Gabriel Genellina
Softlab SRL 


Preguntá. Respondé. Descubrí. 
Todo lo que querías saber, y lo que ni imaginabas, 
está en Yahoo! Respuestas (Beta). 
¡Probalo ya! 

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