pythonpython-3.xwsgiref

Serving JPG files via wsgiref.simple_server in Python 3 - "write() argument must be a bytes instance"


I am trying to make a HTTP server in Python3. For the beginning, I only want a server that serves a single JPG file. Here's my code:

from wsgiref.simple_server import make_server

def simple_app(environ, start_response):
    headers = [('Content-type', 'image/jpeg')]
    start_response('200 OK', headers)
    data = b''
    filename = r'sunset-at-dusk.jpg'
    with open(filename, 'rb', buffering=0) as f:
        data = f.readall()
    print(type(data))       #<class 'bytes'>
    return data

httpd = make_server('', 8001, simple_app)
print("Serving on port 8001...")
httpd.serve_forever()

When I try to access the server via HTTP, I get the following error.

127.0.0.1 - - [01/Jun/2016 08:37:43] "GET / HTTP/1.1" 200 0 Traceback (most recent call last):   File "C:\Anaconda3\lib\wsgiref\handlers.py", line 138, in run
    self.finish_response()   File "C:\Anaconda3\lib\wsgiref\handlers.py", line 180, in finish_response
    self.write(data)   File "C:\Anaconda3\lib\wsgiref\handlers.py", line 266, in write
    "write() argument must be a bytes instance" AssertionError: write() argument must be a bytes instance

'sunset-at-dusk.jpg' is a valid JPG file in the same folder as my script.

What am I doing wrong?


Solution

  • Return data as list

    return [data]