python - twisted image transfer from client to server gives bad format error -

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i trying send image file using tcp server client. tried opening file, reading , transporting using self.transport.write. on client side, when receive data, open file named image in append mode, , write it.

client:

class echoclient(protocol.protocol):     def datareceived(self, data):                  print 'writing file'         f = open('image.png','a')         f.write(data)         f.close()

server (inherits protocol):

//somewhere in code       image = open(self.newdict[device_str] + attribute_str + '.png')      data = image.read()      image.close()      self.comm_protocol.transport.write(data)

opening file on client side gives bad format error. ideas doing wrong ? idea stream image string bad ? if so, there other way can transfer data client ?

you have open file in binary mode, 'b' flag, open(..., 'wb').

the reason file gets corrupted "text mode" 1 of 2 things:

  1. on unix, nothing.
  2. on windows, replaces \n \r\n.

now, if it's text file, can hardly tell difference. but, if it's binary file, byte might doesn't mean "newline" more. generally, binary files constructed fixed-length structures, sticking 2 bytes in 1 expected cause kinds of havoc.


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