Pythonで接続エラーなどのテスト用のダミーWebサーバを作る ref: https://qiita.com/kurogelee/items/e257edb927fc21e87f71

dummy_server.py

from itertools import chain, repeat
from time import sleep

try:
    # python3
    from http.server import HTTPServer, SimpleHTTPRequestHandler
except:
    # python2
    from SimpleHTTPServer import SimpleHTTPRequestHandler
    from BaseHTTPServer import HTTPServer


def close():
    return True, None


def wait(time_seconds, path=None):
    def f():
        sleep(time_seconds)
        return False, path

    return f


def page(path):
    return wait(0, path)


path_map = {
    "/test": chain([close, wait(3, "/dummy_server.py"), None, page("/dummy_server.py")]),
    "/test2": (x for seq in repeat((close, page("/dummy_server.py"))) for x in seq),
    "/dummy_server.py": chain([close, close, wait(1)], repeat(None))
}


class RequestHandler(SimpleHTTPRequestHandler, object):
    def print_info(self):
        self.log_message("%s %s\n%s", self.command, self.path, self.headers)

    def do_GET(self):
        self.print_info()

        iterator = path_map.get(self.path)
        if iterator:
            f = next(iterator, None)
            if f:
                ret, path = f()
                if ret:
                    return
                if path:
                    self.path = path

        super(RequestHandler, self).do_GET()

    def do_POST(self):
        self.do_GET()


httpd = HTTPServer(("", 8000), RequestHandler)
httpd.serve_forever()