TypeError while iterating list of dictionaries in docker container

I have a Django project. I use Wordpress as an admin panel. I call WP API during handling one of views.

Here is the view:

def blog(request):
sys.stderr.write('views.blog started to process\n')
if request.method == 'GET':
    list_of_blogposts = []

    # load all posts
    try:
        response = wp.get_all_post()
        all_posts = json.loads(response.text)
        sys.stderr.write('path /blog - all done' + all_posts)
    except Http404:
        msg = 'Unable to load blogposts.'
        sys.stderr.write(msg)
        raise Http404(msg)
    except TimeoutError:
        msg = 'Requst timed out.'
        sys.stderr.write(msg)
        raise TimeoutError(msg)
    except Exception:
        msg = 'Exception'
        sys.stderr.write(msg + str(traceback.extract_stack()))

    # iterate all posts
    try:
        # get all images
        m = wp.get_all_images()
        media = json.loads(m.text)

        for post in all_posts:
            img = post["featured_media"]
            url = u.get_image_url(media, img)

            b = {
                "body": post["content"]["rendered"],
                "title": post["title"]["rendered"],
                "summary": post["excerpt"]["rendered"],
                "image_url": str(url),
                "post_id": post["id"],
                "publishedAt": u.convert_dt_to_str(post["date"])
            }

            # add post to list for response
            list_of_blogposts.append(b)
    except TypeError or ValueError or RuntimeError or KeyError:
        sys.stderr.write('Iteration through posts failed.')
        raise Exception('Unexpected error. Try again later.')

    context = {'posts_list': list_of_blogposts}
    return render(request, 'web/blog.html', context)
else:
    raise Http404("Incorrect HTTP method.")

It works great as I want. When I create Docker image and run it on linux server I got - TypeError: string indices must be integers, not 'str' at line where is img = post["featured_media"].

I am confused because when I debug the issue I see that post is dictionary and it should be possible to go through like I did.

I appreciate any help or hint. Thank you in advance.

source https://stackoverflow.com/questions/76240243/typeerror-while-iterating-list-of-dictionaries-in-docker-container