Django transfer uploaded file

I'm trying to upload a file via django forms, then send it to an API.

Here's the encoding function:

#FYI, requestFile = request.FILES['file']def EncodeFile(self, requestFile, fields = []):    BOUNDARY    = '----------boundary------'    CRLF        = '\r\n'    body        = []    # Add the metadata about the upload first    for param in fields:        body.extend(          ['--'+ BOUNDARY,'Content-Disposition: form-data; name="%s"' % param,'',           fields[param],           ])    fileContent = requestFile.read()    body.extend(      ['--'+ BOUNDARY,'Content-Disposition: form-data; name="file"; filename="%s"'       % requestFile.name,       # The upload server determines the mime-type, no need to set it.'Content-Type: '+ requestFile.content_type,'',       fileContent,       ])    # Finalize the form body    body.extend(['--'+ BOUNDARY +'--', ''])    result =  'multipart/form-data; boundary=%s' % BOUNDARY, CRLF.join(body)    return result

The problem is that when it reaches "CRLF.join(body)" it complains about "'utf8' codec can't decode byte 0xff in position 0: invalid start byte".

The exact same piece of code works flawlessly from the command line with the exception that the requestFile is actually a path to a file, and I'm doing an open(requestFile, 'rb') before reading the contents.

I can not for the life of me figure out what to do next. I've been googling for an answer for the past 10 hours or so.