test.py

from pydantic import BaseModel

import requests

from returns.context import RequiresContext
from returns.functions import tap
from returns.io import IOResultE, impure_safe


class OVHIpAddr(BaseModel):
    ip: str
    ip_decimal: int
    country: str
    country_eu: bool
    country_iso: str
    city: str
    hostname: str
    latitude: float
    longitude: float
    asn: str
    asn_org: str


def get_ip_addr() -> RequiresContext[str, IOResultE[OVHIpAddr]]:
    """Get our IP address from a service"""

    @impure_safe
    def inner(url: str) -> OVHIpAddr:
        resp = requests.get(url)
        return OVHIpAddr(**resp.json())

    return RequiresContext(inner)


def format_city_country(data: OVHIpAddr) -> str:
    """Format the city and country"""
    return f"{data.city}, {data.country}"


if __name__ == "__main__":
    # Works
    (
        get_ip_addr()("https://whatsmyip.ovh/json")
        .map(format_city_country)
        .map(tap(print))
    )

    # AttributeError: '_IOSuccess' object has no attribute 'city'
    # error: Argument 1 to "map" of "RequiresContext" has incompatible type "Callable[[OVHIpAddr], str]"; expected "Callable[[IOResult[OVHIpAddr, Exception]], str]"
    (
        get_ip_addr()
        .map(format_city_country)
        .map(tap(print))("https://whatsmyip.ovh/json")
    )