Notes

import requests
from fastapi import FastAPI, Form, HTTPException, status
from pydantic import BaseModel, ValidationError


# Replace with your actual CountryStatecity.in API key
API_KEY = "WjdpQWVDRVBTd2NCODJCalpVMERBUjFaRVNaWWNDRjdkTjlRalJrdw=="

# Base models for data validation and type safety
class Country(BaseModel):
iso2: str
name: str

class State(BaseModel):
iso2: str
name: str

class City(BaseModel):
name: str

# Endpoint to fetch all countries
@app.get("/countries")
async def get_countries():
api_url = "https://api.countrystatecity.in/v1/countries"
headers = {"X-CSCAPI-KEY": API_KEY}

try:
response = requests.get(api_url, headers=headers)
response.raise_for_status() # Raise an exception for 4xx/5xx status codes
countries = response.json()
return [Country(**country) for country in countries] # Convert to validated models
except requests.exceptions.RequestException as e:
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail=f"An error occurred while fetching countries: {e}"
)

@app.get("/countries/{country_code}/states")
async def get_states(country_code: str):
api_url = f"https://api.countrystatecity.in/v1/countries/{country_code}/states"
headers = {"X-CSCAPI-KEY": API_KEY}

try:
response = requests.get(api_url, headers=headers)
response.raise_for_status()
states = response.json() # Remove data validation if unnecessary
return states
except requests.exceptions.RequestException as e:
raise HTTPException(
status_code=status.HTTP_404_NOT_FOUND,
detail=f"Country with code '{country_code}' not found, or an error occurred: {e}"
)

# Endpoint to fetch cities for a state
@app.get("/countries/{country_code}/states/{state_code}/cities")
async def get_cities(country_code: str, state_code: str):
api_url = f"https://api.countrystatecity.in/v1/countries/{country_code}/states/{state_code}/cities"
headers = {"X-CSCAPI-KEY": API_KEY}

try:
response = requests.get(api_url, headers=headers)
response.raise_for_status()
cities = response.json()
return [City(**city) for city in cities] # Convert to validated models
except requests.exceptions.RequestException as e:
raise HTTPException(
status_code=status.HTTP_404_NOT_FOUND,
detail=f"State with code '{state_code}' in country '{country_code}' not found, or an error occurred: {e}"
)