How to retrieving image from postgresql ? image is stored in binaryformat

images=db.execute("SELECT encode(img::bytea, 'base64') from images where imgid = 1").fetchall()
    
    
    for i in images:
        for k in i:
            imgdata=b64decode(k)
            filename = 'some_image.jpg'  # I assume you have a way of picking unique filenames
            with open(filename, 'wb') as f:
                f.write(imgdata)

* Running on http://localhost:9000/ (Press CTRL+C to quit)
127.0.0.1 - - [25/Jun/2018 23:55:06] "GET / HTTP/1.1" 200 -
[2018-06-25 23:55:09,283] ERROR in app: Exception on /download [POST]
Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\flask\app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\ProgramData\Anaconda3\lib\site-packages\flask\app.py", line 1816, in full_dispatch_request
    return self.finalize_request(rv)
  File "C:\ProgramData\Anaconda3\lib\site-packages\flask\app.py", line 1831, in finalize_request
    response = self.make_response(rv)
  File "C:\ProgramData\Anaconda3\lib\site-packages\flask\app.py", line 1957, in make_response
    'The view function did not return a valid response. The'
TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement.