Writing byte stream as jpeg format to disk

[MRAB]

On 26/08/2010 21:14, Navkirat Singh wrote:
>
> On 27-Aug-2010, at 1:32 AM, Dave Angel wrote:
>
>> Navkirat Singh wrote:
>>> Hey guys,
>>>
>>> I am programming a webserver, I receive a jpeg file with the POST
>>> method.The file (.jpeg) is encoded in bytes, I parse the bytes by
>>> decoding them to a string. I wanted to know how i could write the
>>> file (now a string) as a jpeg image on disk. When I try to encode the
>>> same string to a bytes and write them in binary format to disk, the
>>> file is not recognized as jpeg. I would be grateful if someone could
>>> help me with this.
>>>
>>>
>>> Regards,
>>> Nav
>> If by "decoding them to a string" you mean converting to Unicode, then
>> you've already trashed the data. That's only valid if the bytes had
>> been encoded from valid Unicode characters, and then only if you use
>> the corresponding decoding technique.
>>
>> If you mean some other decoding, then the question is meaningless
>> without telling us just what the decoding is, preferably with some code.
>>
>> It also might be useful to know what version of Python you're using,
>> when you post the code.
>>
>> DaveA
>>
>
> Dave,
>
> I am using Python3 and I receive a byte stream with a jpeg attached sent
> by the web browser over a socket, which looks like this:
>
> b': image/jpeg\r\nAccept: text/*\r\nReferer:
> http://127.0.0.1:8001/\r\nAccept-Language: en-us\r\nAccept-Encoding:
> gzip, deflate\r\nContent-Length: 91783\r\nConnection:
> keep-alive\r\n\r\n\xff\xd8\xff\xe0\x00\x10JFIF\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb\x00\x84\x00\x03\x02\x02\x03\x02\x02\x03\x03\x03\x03\x04\x03\x03\x04\x05\x08\x05\x05\x04\x04\x05\n\x07\x07\x06\x08\x0c\n\x0c\x0c\x0b\n\x0b\x0b\r\x0e\x12\x10\r\x0e\x11\x0e\x0b\x0b\x10\x16\x10\x11\x13\x14\x15\x15\x15\x0c\x0f
>
>  From the above, I need to:
>
> a) Split the header content from the image content, which comes after
> the keep-alive\r\n\r\n part
>
> b) Then write the image content to file for further use as a jpeg.
>
Try:

     image = header.split(b'keep-alive\r\n\r\n', 1)[-1]
     open(image_path, 'wb').write(image)