A list which only accepts URLs.

list_06_urlfilter.py

from collections import UserList
from urllib.parse import urlparse
import json
import requests


def recursive_key_values(dictionary):
    for key, value in dictionary.items():
        i = 0
        if type(value) is str:
            yield (key, value)
        elif type(value) is dict:
            yield from recursive_key_values(value)
        elif type(value) in (list, tuple, set):
            for seq_item in value:
                yield from recursive_key_values({f"{key}_{str(i)}": seq_item})
                i = i + 1
        else:
            yield (key, str(value))


class URLFilteredList(UserList):
    """
    URLFilteredList. Will only accept URLs via append.
    """
    def __init__(self):
        self.data = []

    def append(self, item) -> None:
        if self._is_url(item):
            super().append(item)

    def __setitem__(self, i: int, item):
        if self._is_url(item):
            super().append(item)

    @staticmethod
    def _is_url(value: str) -> bool:
        if value and isinstance(value, str):
            validation = urlparse(value)
            if all([validation.scheme, validation.netloc]):
                return True

        return False


dict1 = dict(
    json.loads(
        requests.get("http://ergast.com/api/f1/2014/5/results.json").text))

ul: URLFilteredList = URLFilteredList()
for k, v in recursive_key_values(dict1):
    ul.append(v)

assert "http://en.wikipedia.org/wiki/2014_Spanish_Grand_Prix" in ul
assert "http://en.wikipedia.org/wiki/Daniel_Ricciardo" in ul
ul[0] = "definitely not a url"
assert ul[0] == 'http://ergast.com/mrd/1.4'

print(ul)