Flask pytest: FAILED tests/test_data_response.py::test_post_data_response - TypeError: Object of type HTTPResponse is not JSON serializable

Question

Flask pytest fails with an error. TypeError: Object of type HTTPResponse is not JSON serializable.

self = <json.encoder.JSONEncoder object at 0x10648f610>, o = <http.client.HTTPResponse object at 0x10849db70>

Default message with the error. Implement this method in a subclass such that it returns a serializable object for o, or calls the base implementation.

   def default(self, o):
     try: iterable = iter(o) 
    except TypeError: pass 
    else: return list(iterable) –

THIS LINE IS CAUSING AN ERROR from PYTEST.

search_page=urlopen(url_for('discovery_bp.search_fund', _external=True))

If I pass the hardcoded URL, it works fine but when I pass the route, I get an error TypeError: Object of type HTTPResponse is not JSON serializable

rouets file

@discovery_bp.route('/', methods=['GET', 'POST'])
def search_fund():
    """ 
    Given function creates a text field for search box &
    renders on index.html then 
    retrieves input data from the user, run that data through 
    function query_fund from data.py to grab the fund 
    & renders back onto index.html 
    """
    form = SearchForm()
    if form.validate_on_submit():
        query = form.search.data.split(" ")
        fund_results = query_fund(query, f"{FUND_STORE_API_HOST}/{FUND_ENDPOINT}")
        return render_template("search.html", query =query, 
                              fund_results = fund_results,
                              form=form)
    return render_template("search.html", form=form)    

Selenium class

@dataclass
class SeleniumElements:
    search_page: str
    response_page: str
    selenium_id: str
    selenium_class: str
    search_data: str
    driver: str
    
    def element_search_max_time(self,sec):
        return self.driver.implicitly_wait(sec)
  
    def get_data(self):
        self.driver.get(self.search_page)
        self.element_search_max_time(30)
        to_search = self.driver.find_element(By.ID, self.selenium_id)
        to_search.click()
        to_search.send_keys(self.search_data)
        submit = self.driver.find_element(By.CLASS_NAME,self.selenium_class)
        submit.click()
        self.element_search_max_time(30)
        fund_response = requests.get(self.search_page)
        assert fund_response.status_code == 200
        self.element_search_max_time(30)
        round_store_href_link = self.driver.find_element(
            By.XPATH, '//*[@id="main-content"]/div[4]/div/h1/a')
        round_store_href_link.click()
        self.element_search_max_time(30)
        rounds_response = requests.get(self.response_page)
        assert rounds_response.status_code == 200

This is the test file & I am trying to use the live service method from pytest so I can grab the route instead of hardcoded URL.

@pytest.mark.usefixtures("selenium_chrome_driver")
@pytest.mark.usefixtures('live_server')
def test_post_data_response():`enter code here`
    search_response = SeleniumElements(
        search_page=urlopen(url_for('discovery_bp.search_fund', _external=True)),
        response_page=RESPONSE_PAGE,
        selenium_id=SEARCH_BOX_ID,
        selenium_class=SUBMIT_BUTTON_CLASS,
        search_data=SEARCH_KEYWORD,
        driver =chrome_driver)
    search_response.get_data()