A simplicidade e o poderoso ecossistema do Python o tornam uma excelente escolha para integrar verificação de email em suas aplicações. Seja construindo uma aplicação web com Django ou Flask, processando dados com pandas, ou criando fluxos de trabalho automatizados, adicionar verificação profissional de email garante que suas comunicações por email alcancem destinatários reais e protege sua reputação de remetente.
Este guia completo orienta você através da integração da API de verificação de email BillionVerify com Python, desde a verificação básica de email individual até processamento em lote avançado e implementações prontas para produção.
Pré-requisitos e Configuração
Antes de mergulhar no código, certifique-se de ter o ambiente adequado configurado. Este tutorial assume que você tem Python 3.8 ou superior instalado em seu sistema.
Instalando Pacotes Necessários
Comece instalando os pacotes necessários. Usaremos a biblioteca requests para comunicação HTTP, embora também exploraremos aiohttp para operações assíncronas mais tarde.
pip install requests python-dotenv
Para suporte assíncrono e recursos avançados:
pip install aiohttp pandas
Estrutura do Projeto
Organize seu projeto com uma estrutura limpa que separa as responsabilidades:
email_verification/
├── __init__.py
├── client.py # Cliente principal de verificação
├── models.py # Modelos de dados
├── exceptions.py # Exceções personalizadas
├── utils.py # Funções auxiliares
├── batch_processor.py # Lógica de verificação em lote
└── examples/
├── basic_usage.py
├── flask_integration.py
└── django_integration.py
Configuração do Ambiente
Crie um arquivo .env para armazenar suas credenciais de API de forma segura:
EMAILVERIFY_API_KEY=your_api_key_here EMAILVERIFY_API_URL=https://api.billionverify.com/v1
Carregue essas variáveis em sua aplicação:
import os
from dotenv import load_dotenv
load_dotenv()
API_KEY = os.getenv('EMAILVERIFY_API_KEY')
API_URL = os.getenv('EMAILVERIFY_API_URL', 'https://api.billionverify.com/v1')
Verificação Básica de Email
Vamos começar com a implementação mais simples: verificar um único endereço de email usando a biblioteca requests do Python.
Função de Verificação Simples
import requests
from typing import Dict, Any
def verify_email(email: str, api_key: str) -> Dict[str, Any]:
"""
Verify a single email address using the BillionVerify API.
Args:
email: The email address to verify
api_key: Your BillionVerify API key
Returns:
Dictionary containing verification results
Raises:
requests.RequestException: If the API request fails
"""
url = "https://api.billionverify.com/v1/verify"
headers = {
"Authorization": f"Bearer {api_key}",
"Content-Type": "application/json"
}
payload = {"email": email}
response = requests.post(url, json=payload, headers=headers, timeout=30)
response.raise_for_status()
return response.json()
# Example usage
if __name__ == "__main__":
result = verify_email("test@example.com", API_KEY)
print(f"Email valid: {result.get('is_valid')}")
print(f"Deliverable: {result.get('is_deliverable')}")
Compreendendo a Resposta
A API retorna uma resposta abrangente com múltiplos indicadores de verificação:
{
"email": "user@example.com",
"is_valid": True,
"is_deliverable": True,
"is_disposable": False,
"is_role_based": False,
"is_catch_all": False,
"is_free_provider": True,
"risk_score": 15,
"domain": "example.com",
"mx_records": ["mx1.example.com", "mx2.example.com"],
"smtp_check": True,
"verification_time_ms": 245
}
Cada campo fornece informações valiosas:
- is_valid: Se o formato do email está sintaticamente correto
- is_deliverable: Se a caixa de correio existe e pode receber emails
- is_disposable: Identifica endereços de email temporários ou descartáveis
- is_role_based: Detecta endereços genéricos como info@ ou support@
- is_catch_all: Indica domínios que aceitam todos os endereços
- risk_score: Avaliação numérica de 0 (menor risco) a 100 (maior risco)
Construindo um Cliente Pronto para Produção
Para aplicações em produção, você precisa de uma classe de cliente robusta que lide com autenticação, tentativas repetidas, limitação de taxa e tratamento de erros de forma elegante.
Exceções Personalizadas
Primeiro, defina exceções personalizadas para melhor tratamento de erros:
# exceptions.py
class EmailVerificationError(Exception):
"""Base exception for email verification errors."""
pass
class AuthenticationError(EmailVerificationError):
"""Raised when API authentication fails."""
pass
class RateLimitError(EmailVerificationError):
"""Raised when API rate limit is exceeded."""
def __init__(self, retry_after: int = 60):
self.retry_after = retry_after
super().__init__(f"Rate limit exceeded. Retry after {retry_after} seconds.")
class ValidationError(EmailVerificationError):
"""Raised when email validation fails."""
pass
class APIError(EmailVerificationError):
"""Raised for general API errors."""
def __init__(self, status_code: int, message: str):
self.status_code = status_code
super().__init__(f"API error {status_code}: {message}")
Modelos de Dados
Use dataclasses ou Pydantic para tratamento de resposta com segurança de tipo:
# models.py
from dataclasses import dataclass
from typing import List, Optional
@dataclass
class VerificationResult:
"""Represents the result of an email verification."""
email: str
is_valid: bool
is_deliverable: bool
is_disposable: bool
is_role_based: bool
is_catch_all: bool
is_free_provider: bool
risk_score: int
domain: str
mx_records: List[str]
smtp_check: bool
verification_time_ms: int
@classmethod
def from_dict(cls, data: dict) -> 'VerificationResult':
"""Create a VerificationResult from API response dictionary."""
return cls(
email=data.get('email', ''),
is_valid=data.get('is_valid', False),
is_deliverable=data.get('is_deliverable', False),
is_disposable=data.get('is_disposable', False),
is_role_based=data.get('is_role_based', False),
is_catch_all=data.get('is_catch_all', False),
is_free_provider=data.get('is_free_provider', False),
risk_score=data.get('risk_score', 100),
domain=data.get('domain', ''),
mx_records=data.get('mx_records', []),
smtp_check=data.get('smtp_check', False),
verification_time_ms=data.get('verification_time_ms', 0)
)
def is_safe_to_send(self) -> bool:
"""Determine if it's safe to send emails to this address."""
return (
self.is_valid and
self.is_deliverable and
not self.is_disposable and
self.risk_score < 50
)
A Classe Cliente Principal
Agora implemente o cliente de verificação completo:
# client.py
import time
import logging
from typing import Optional, List
import requests
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry
from .models import VerificationResult
from .exceptions import (
AuthenticationError,
RateLimitError,
ValidationError,
APIError
)
logger = logging.getLogger(__name__)
class EmailVerificationClient:
"""
Production-ready client for the BillionVerify email verification API.
Features:
- Automatic retry with exponential backoff
- Rate limit handling
- Connection pooling
- Comprehensive error handling
- Response caching (optional)
"""
DEFAULT_BASE_URL = "https://api.billionverify.com/v1"
DEFAULT_TIMEOUT = 30
MAX_RETRIES = 3
def __init__(
self,
api_key: str,
base_url: Optional[str] = None,
timeout: int = DEFAULT_TIMEOUT,
max_retries: int = MAX_RETRIES
):
"""
Initialize the email verification client.
Args:
api_key: Your BillionVerify API key
base_url: Optional custom API base URL
timeout: Request timeout in seconds
max_retries: Maximum number of retry attempts
"""
if not api_key:
raise ValueError("API key is required")
self.api_key = api_key
self.base_url = base_url or self.DEFAULT_BASE_URL
self.timeout = timeout
self.max_retries = max_retries
# Configure session with retry logic
self.session = self._create_session()
def _create_session(self) -> requests.Session:
"""Create a requests session with retry configuration."""
session = requests.Session()
# Configure retry strategy
retry_strategy = Retry(
total=self.max_retries,
backoff_factor=1,
status_forcelist=[429, 500, 502, 503, 504],
allowed_methods=["GET", "POST"]
)
adapter = HTTPAdapter(
max_retries=retry_strategy,
pool_connections=10,
pool_maxsize=20
)
session.mount("http://", adapter)
session.mount("https://", adapter)
# Set default headers
session.headers.update({
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json",
"User-Agent": "BillionVerify-Python/1.0"
})
return session
def _handle_response(self, response: requests.Response) -> dict:
"""
Handle API response and raise appropriate exceptions.
Args:
response: The requests Response object
Returns:
Parsed JSON response
Raises:
AuthenticationError: For 401/403 responses
RateLimitError: For 429 responses
APIError: For other error responses
"""
if response.status_code == 401:
raise AuthenticationError("Invalid API key")
if response.status_code == 403:
raise AuthenticationError("Access forbidden. Check API key permissions.")
if response.status_code == 429:
retry_after = int(response.headers.get('Retry-After', 60))
raise RateLimitError(retry_after)
if response.status_code == 400:
error_data = response.json()
raise ValidationError(error_data.get('message', 'Validation failed'))
if response.status_code >= 400:
raise APIError(response.status_code, response.text)
return response.json()
def verify(self, email: str) -> VerificationResult:
"""
Verify a single email address.
Args:
email: The email address to verify
Returns:
VerificationResult object with verification details
"""
url = f"{self.base_url}/verify"
logger.debug(f"Verifying email: {email}")
response = self.session.post(
url,
json={"email": email},
timeout=self.timeout
)
data = self._handle_response(response)
result = VerificationResult.from_dict(data)
logger.info(
f"Verified {email}: valid={result.is_valid}, "
f"deliverable={result.is_deliverable}, "
f"risk_score={result.risk_score}"
)
return result
def verify_batch(
self,
emails: List[str],
callback_url: Optional[str] = None
) -> str:
"""
Submit a batch of emails for verification.
Args:
emails: List of email addresses to verify
callback_url: Optional webhook URL for results notification
Returns:
Batch ID for tracking the verification job
"""
url = f"{self.base_url}/verify/batch"
payload = {"emails": emails}
if callback_url:
payload["callback_url"] = callback_url
response = self.session.post(
url,
json=payload,
timeout=self.timeout
)
data = self._handle_response(response)
batch_id = data.get('batch_id')
logger.info(f"Submitted batch verification: {batch_id} ({len(emails)} emails)")
return batch_id
def get_batch_status(self, batch_id: str) -> dict:
"""
Get the status of a batch verification job.
Args:
batch_id: The batch ID returned from verify_batch
Returns:
Dictionary with batch status and progress
"""
url = f"{self.base_url}/verify/batch/{batch_id}"
response = self.session.get(url, timeout=self.timeout)
return self._handle_response(response)
def get_batch_results(self, batch_id: str) -> List[VerificationResult]:
"""
Get the results of a completed batch verification.
Args:
batch_id: The batch ID returned from verify_batch
Returns:
List of VerificationResult objects
"""
url = f"{self.base_url}/verify/batch/{batch_id}/results"
response = self.session.get(url, timeout=self.timeout)
data = self._handle_response(response)
return [VerificationResult.from_dict(item) for item in data.get('results', [])]
def close(self):
"""Close the underlying session."""
self.session.close()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
Verificação de Email em Lote
Processar grandes listas de email requer manipulação eficiente em lote. Aqui está como implementar verificação em lote robusta com rastreamento de progresso e gerenciamento de resultados.
Implementação do Processador em Lote
# batch_processor.py
import time
import logging
from typing import List, Callable, Optional
from concurrent.futures import ThreadPoolExecutor, as_completed
from .client import EmailVerificationClient
from .models import VerificationResult
from .exceptions import RateLimitError
logger = logging.getLogger(__name__)
class BatchProcessor:
"""
Process large email lists with progress tracking and result handling.
"""
def __init__(
self,
client: EmailVerificationClient,
batch_size: int = 1000,
max_workers: int = 5,
progress_callback: Optional[Callable[[int, int], None]] = None
):
"""
Initialize the batch processor.
Args:
client: EmailVerificationClient instance
batch_size: Number of emails per batch submission
max_workers: Maximum concurrent verification threads
progress_callback: Optional callback for progress updates
"""
self.client = client
self.batch_size = batch_size
self.max_workers = max_workers
self.progress_callback = progress_callback
def process_list(
self,
emails: List[str],
use_async_batch: bool = True
) -> List[VerificationResult]:
"""
Process a list of emails with optimal strategy.
Args:
emails: List of email addresses
use_async_batch: Use async batch API for large lists
Returns:
List of verification results
"""
total = len(emails)
logger.info(f"Starting verification of {total} emails")
if total <= 10:
# Small list: verify individually
return self._process_sequential(emails)
elif use_async_batch and total > 100:
# Large list: use batch API
return self._process_batch_api(emails)
else:
# Medium list: use concurrent individual verification
return self._process_concurrent(emails)
def _process_sequential(
self,
emails: List[str]
) -> List[VerificationResult]:
"""Process emails sequentially."""
results = []
total = len(emails)
for i, email in enumerate(emails):
try:
result = self.client.verify(email)
results.append(result)
except RateLimitError as e:
logger.warning(f"Rate limit hit, waiting {e.retry_after}s")
time.sleep(e.retry_after)
result = self.client.verify(email)
results.append(result)
except Exception as e:
logger.error(f"Failed to verify {email}: {e}")
results.append(self._create_error_result(email, str(e)))
if self.progress_callback:
self.progress_callback(i + 1, total)
return results
def _process_concurrent(
self,
emails: List[str]
) -> List[VerificationResult]:
"""Process emails concurrently with thread pool."""
results = []
total = len(emails)
completed = 0
with ThreadPoolExecutor(max_workers=self.max_workers) as executor:
future_to_email = {
executor.submit(self._verify_with_retry, email): email
for email in emails
}
for future in as_completed(future_to_email):
email = future_to_email[future]
try:
result = future.result()
results.append(result)
except Exception as e:
logger.error(f"Failed to verify {email}: {e}")
results.append(self._create_error_result(email, str(e)))
completed += 1
if self.progress_callback:
self.progress_callback(completed, total)
return results
def _process_batch_api(
self,
emails: List[str]
) -> List[VerificationResult]:
"""Process emails using the async batch API."""
all_results = []
total = len(emails)
processed = 0
# Split into batches
batches = [
emails[i:i + self.batch_size]
for i in range(0, total, self.batch_size)
]
for batch_num, batch in enumerate(batches, 1):
logger.info(f"Submitting batch {batch_num}/{len(batches)}")
# Submit batch
batch_id = self.client.verify_batch(batch)
# Wait for completion with polling
results = self._wait_for_batch(batch_id)
all_results.extend(results)
processed += len(batch)
if self.progress_callback:
self.progress_callback(processed, total)
return all_results
def _wait_for_batch(
self,
batch_id: str,
poll_interval: int = 5,
max_wait: int = 3600
) -> List[VerificationResult]:
"""
Wait for batch verification to complete.
Args:
batch_id: The batch ID to wait for
poll_interval: Seconds between status checks
max_wait: Maximum seconds to wait
Returns:
List of verification results
"""
start_time = time.time()
while time.time() - start_time < max_wait:
status = self.client.get_batch_status(batch_id)
if status.get('status') == 'completed':
return self.client.get_batch_results(batch_id)
if status.get('status') == 'failed':
raise RuntimeError(f"Batch {batch_id} failed: {status.get('error')}")
progress = status.get('progress', 0)
logger.debug(f"Batch {batch_id} progress: {progress}%")
time.sleep(poll_interval)
raise TimeoutError(f"Batch {batch_id} did not complete within {max_wait}s")
def _verify_with_retry(
self,
email: str,
max_retries: int = 3
) -> VerificationResult:
"""Verify email with retry logic for rate limits."""
for attempt in range(max_retries):
try:
return self.client.verify(email)
except RateLimitError as e:
if attempt < max_retries - 1:
time.sleep(e.retry_after)
else:
raise
raise RuntimeError(f"Failed to verify {email} after {max_retries} attempts")
@staticmethod
def _create_error_result(email: str, error: str) -> VerificationResult:
"""Create a result object for failed verification."""
return VerificationResult(
email=email,
is_valid=False,
is_deliverable=False,
is_disposable=False,
is_role_based=False,
is_catch_all=False,
is_free_provider=False,
risk_score=100,
domain=email.split('@')[-1] if '@' in email else '',
mx_records=[],
smtp_check=False,
verification_time_ms=0
)
Trabalhando com Arquivos CSV e Pandas
Para fluxos de trabalho de processamento de dados, integre com pandas:
import pandas as pd
from typing import Optional
def verify_csv_file(
client: EmailVerificationClient,
input_file: str,
output_file: str,
email_column: str = 'email',
batch_size: int = 1000
) -> pd.DataFrame:
"""
Verify emails from a CSV file and save results.
Args:
client: EmailVerificationClient instance
input_file: Path to input CSV file
output_file: Path to output CSV file
email_column: Name of the column containing emails
batch_size: Processing batch size
Returns:
DataFrame with verification results
"""
# Read input file
df = pd.read_csv(input_file)
if email_column not in df.columns:
raise ValueError(f"Column '{email_column}' not found in CSV")
emails = df[email_column].dropna().tolist()
# Process with progress tracking
processor = BatchProcessor(
client,
batch_size=batch_size,
progress_callback=lambda done, total: print(f"Progress: {done}/{total}")
)
results = processor.process_list(emails)
# Create results DataFrame
results_df = pd.DataFrame([
{
'email': r.email,
'is_valid': r.is_valid,
'is_deliverable': r.is_deliverable,
'is_disposable': r.is_disposable,
'is_role_based': r.is_role_based,
'is_catch_all': r.is_catch_all,
'risk_score': r.risk_score,
'domain': r.domain
}
for r in results
])
# Merge with original data
merged = df.merge(results_df, left_on=email_column, right_on='email', how='left')
# Save results
merged.to_csv(output_file, index=False)
# Print summary
print(f"\nVerification Summary:")
print(f" Total emails: {len(emails)}")
print(f" Valid: {results_df['is_valid'].sum()}")
print(f" Deliverable: {results_df['is_deliverable'].sum()}")
print(f" Disposable: {results_df['is_disposable'].sum()}")
print(f" High risk (score >= 50): {(results_df['risk_score'] >= 50).sum()}")
return merged
Verificação Assíncrona com asyncio
Para aplicações de alto desempenho, use o asyncio do Python com aiohttp:
import asyncio
import aiohttp
from typing import List, Optional
from dataclasses import dataclass
class AsyncEmailVerificationClient:
"""
Asynchronous email verification client using aiohttp.
"""
def __init__(
self,
api_key: str,
base_url: str = "https://api.billionverify.com/v1",
concurrency_limit: int = 10
):
self.api_key = api_key
self.base_url = base_url
self.semaphore = asyncio.Semaphore(concurrency_limit)
self._session: Optional[aiohttp.ClientSession] = None
async def _get_session(self) -> aiohttp.ClientSession:
"""Get or create aiohttp session."""
if self._session is None or self._session.closed:
self._session = aiohttp.ClientSession(
headers={
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json"
}
)
return self._session
async def verify(self, email: str) -> dict:
"""Verify a single email asynchronously."""
async with self.semaphore:
session = await self._get_session()
url = f"{self.base_url}/verify"
async with session.post(url, json={"email": email}) as response:
if response.status == 429:
retry_after = int(response.headers.get('Retry-After', 60))
await asyncio.sleep(retry_after)
return await self.verify(email)
response.raise_for_status()
return await response.json()
async def verify_many(self, emails: List[str]) -> List[dict]:
"""Verify multiple emails concurrently."""
tasks = [self.verify(email) for email in emails]
results = await asyncio.gather(*tasks, return_exceptions=True)
return [
r if not isinstance(r, Exception) else {"email": emails[i], "error": str(r)}
for i, r in enumerate(results)
]
async def close(self):
"""Close the aiohttp session."""
if self._session and not self._session.closed:
await self._session.close()
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc_val, exc_tb):
await self.close()
# Usage example
async def main():
emails = [
"user1@example.com",
"user2@example.com",
"user3@example.com"
]
async with AsyncEmailVerificationClient(api_key="your_key") as client:
results = await client.verify_many(emails)
for result in results:
if "error" in result:
print(f"Error: {result['error']}")
else:
print(f"{result['email']}: valid={result['is_valid']}")
# Run the async function
asyncio.run(main())
Integração com Flask
Integre a verificação de email em uma aplicação web Flask:
from flask import Flask, request, jsonify
from functools import wraps
import os
from email_verification import EmailVerificationClient, ValidationError
app = Flask(__name__)
# Initialize client once
verification_client = EmailVerificationClient(
api_key=os.getenv('EMAILVERIFY_API_KEY')
)
def verify_email_param(f):
"""Decorator to verify email parameter in requests."""
@wraps(f)
def decorated_function(*args, **kwargs):
email = request.json.get('email') if request.is_json else request.form.get('email')
if not email:
return jsonify({"error": "Email is required"}), 400
try:
result = verification_client.verify(email)
if not result.is_deliverable:
return jsonify({
"error": "Please provide a valid email address",
"details": {
"is_disposable": result.is_disposable,
"risk_score": result.risk_score
}
}), 400
# Attach result to request for use in route
request.email_verification = result
except ValidationError as e:
return jsonify({"error": str(e)}), 400
except Exception as e:
# Log error but don't block user
app.logger.error(f"Email verification failed: {e}")
return f(*args, **kwargs)
return decorated_function
@app.route('/api/register', methods=['POST'])
@verify_email_param
def register():
"""User registration endpoint with email verification."""
data = request.json
# Email has been verified by decorator
email = data.get('email')
verification = getattr(request, 'email_verification', None)
# Warn about disposable emails but allow
warning = None
if verification and verification.is_disposable:
warning = "You're using a disposable email. Some features may be limited."
# Create user (your implementation)
user = create_user(email=email, **data)
response = {"success": True, "user_id": user.id}
if warning:
response["warning"] = warning
return jsonify(response), 201
@app.route('/api/verify-email', methods=['POST'])
def verify_email_endpoint():
"""Standalone email verification endpoint."""
email = request.json.get('email')
if not email:
return jsonify({"error": "Email is required"}), 400
try:
result = verification_client.verify(email)
return jsonify({
"email": result.email,
"is_valid": result.is_valid,
"is_deliverable": result.is_deliverable,
"is_disposable": result.is_disposable,
"risk_score": result.risk_score,
"safe_to_send": result.is_safe_to_send()
})
except ValidationError as e:
return jsonify({"error": str(e)}), 400
except Exception as e:
return jsonify({"error": "Verification service unavailable"}), 503
if __name__ == '__main__':
app.run(debug=True)
Integração com Django
Para aplicações Django, crie um validador de formulário reutilizável e middleware:
# validators.py
from django.core.exceptions import ValidationError
from django.conf import settings
from email_verification import EmailVerificationClient
def get_verification_client():
"""Get or create verification client."""
if not hasattr(get_verification_client, '_client'):
get_verification_client._client = EmailVerificationClient(
api_key=settings.EMAILVERIFY_API_KEY
)
return get_verification_client._client
def validate_email_deliverable(email: str) -> None:
"""
Django validator to check email deliverability.
Usage in forms:
email = forms.EmailField(validators=[validate_email_deliverable])
"""
client = get_verification_client()
try:
result = client.verify(email)
if not result.is_valid:
raise ValidationError("Please enter a valid email address.")
if not result.is_deliverable:
raise ValidationError(
"This email address doesn't appear to exist. "
"Please check for typos."
)
if result.is_disposable:
raise ValidationError(
"Please use a permanent email address, "
"not a disposable one."
)
except ValidationError:
raise
except Exception as e:
# Log but don't block on service errors
import logging
logging.error(f"Email verification failed: {e}")
# forms.py
from django import forms
from .validators import validate_email_deliverable
class RegistrationForm(forms.Form):
email = forms.EmailField(
validators=[validate_email_deliverable],
help_text="We'll send a confirmation email to this address."
)
password = forms.CharField(widget=forms.PasswordInput)
def clean_email(self):
email = self.cleaned_data['email']
# Additional cleaning if needed
return email.lower().strip()
# middleware.py
from django.http import JsonResponse
from django.conf import settings
class EmailVerificationMiddleware:
"""
Middleware to verify emails in API requests.
Add to MIDDLEWARE setting:
'myapp.middleware.EmailVerificationMiddleware',
"""
VERIFICATION_PATHS = ['/api/register/', '/api/contact/']
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
# Check if path needs verification
if request.path in self.VERIFICATION_PATHS and request.method == 'POST':
import json
try:
data = json.loads(request.body)
email = data.get('email')
if email:
from .validators import get_verification_client
client = get_verification_client()
result = client.verify(email)
if not result.is_safe_to_send():
return JsonResponse({
'error': 'Invalid email address',
'details': {
'is_valid': result.is_valid,
'is_deliverable': result.is_deliverable,
'is_disposable': result.is_disposable
}
}, status=400)
# Attach to request for views
request.email_verification = result
except (json.JSONDecodeError, Exception):
pass
return self.get_response(request)
Cache de Resposta
Reduza chamadas de API e melhore o desempenho com cache inteligente:
import hashlib
import json
import time
from typing import Optional
from functools import lru_cache
class CachedEmailVerificationClient(EmailVerificationClient):
"""
Email verification client with response caching.
"""
def __init__(
self,
api_key: str,
cache_ttl: int = 86400, # 24 hours default
**kwargs
):
super().__init__(api_key, **kwargs)
self.cache_ttl = cache_ttl
self._cache = {}
def _cache_key(self, email: str) -> str:
"""Generate cache key from email."""
normalized = email.lower().strip()
return hashlib.md5(normalized.encode()).hexdigest()
def verify(self, email: str, skip_cache: bool = False) -> VerificationResult:
"""
Verify email with caching.
Args:
email: Email to verify
skip_cache: Force fresh verification
Returns:
VerificationResult from cache or API
"""
cache_key = self._cache_key(email)
# Check cache
if not skip_cache and cache_key in self._cache:
cached_data, cached_time = self._cache[cache_key]
if time.time() - cached_time < self.cache_ttl:
return cached_data
# Fetch from API
result = super().verify(email)
# Cache result
self._cache[cache_key] = (result, time.time())
return result
def clear_cache(self):
"""Clear all cached results."""
self._cache.clear()
def remove_from_cache(self, email: str):
"""Remove specific email from cache."""
cache_key = self._cache_key(email)
self._cache.pop(cache_key, None)
# Redis-based caching for distributed systems
import redis
class RedisCachedClient(EmailVerificationClient):
"""Email verification client with Redis caching."""
def __init__(
self,
api_key: str,
redis_url: str = "redis://localhost:6379",
cache_ttl: int = 86400,
**kwargs
):
super().__init__(api_key, **kwargs)
self.redis = redis.from_url(redis_url)
self.cache_ttl = cache_ttl
self.cache_prefix = "email_verify:"
def verify(self, email: str, skip_cache: bool = False) -> VerificationResult:
"""Verify with Redis caching."""
cache_key = f"{self.cache_prefix}{email.lower().strip()}"
# Check cache
if not skip_cache:
cached = self.redis.get(cache_key)
if cached:
data = json.loads(cached)
return VerificationResult.from_dict(data)
# Fetch from API
result = super().verify(email)
# Cache result
self.redis.setex(
cache_key,
self.cache_ttl,
json.dumps({
'email': result.email,
'is_valid': result.is_valid,
'is_deliverable': result.is_deliverable,
'is_disposable': result.is_disposable,
'is_role_based': result.is_role_based,
'is_catch_all': result.is_catch_all,
'is_free_provider': result.is_free_provider,
'risk_score': result.risk_score,
'domain': result.domain,
'mx_records': result.mx_records,
'smtp_check': result.smtp_check,
'verification_time_ms': result.verification_time_ms
})
)
return result
Testando Sua Integração
Escreva testes abrangentes para garantir que sua integração funcione corretamente:
import pytest
from unittest.mock import Mock, patch
from email_verification import EmailVerificationClient
from email_verification.models import VerificationResult
from email_verification.exceptions import AuthenticationError, RateLimitError
@pytest.fixture
def client():
"""Create test client."""
return EmailVerificationClient(api_key="test_key")
@pytest.fixture
def mock_response():
"""Create mock API response."""
return {
"email": "test@example.com",
"is_valid": True,
"is_deliverable": True,
"is_disposable": False,
"is_role_based": False,
"is_catch_all": False,
"is_free_provider": False,
"risk_score": 10,
"domain": "example.com",
"mx_records": ["mx.example.com"],
"smtp_check": True,
"verification_time_ms": 150
}
class TestEmailVerificationClient:
"""Tests for EmailVerificationClient."""
def test_verify_valid_email(self, client, mock_response):
"""Test successful email verification."""
with patch.object(client.session, 'post') as mock_post:
mock_post.return_value.status_code = 200
mock_post.return_value.json.return_value = mock_response
result = client.verify("test@example.com")
assert result.is_valid is True
assert result.is_deliverable is True
assert result.risk_score == 10
def test_verify_disposable_email(self, client):
"""Test detection of disposable email."""
mock_data = {
"email": "temp@mailinator.com",
"is_valid": True,
"is_deliverable": True,
"is_disposable": True,
"is_role_based": False,
"is_catch_all": False,
"is_free_provider": False,
"risk_score": 80,
"domain": "mailinator.com",
"mx_records": [],
"smtp_check": True,
"verification_time_ms": 100
}
with patch.object(client.session, 'post') as mock_post:
mock_post.return_value.status_code = 200
mock_post.return_value.json.return_value = mock_data
result = client.verify("temp@mailinator.com")
assert result.is_disposable is True
assert result.risk_score == 80
assert result.is_safe_to_send() is False
def test_authentication_error(self, client):
"""Test handling of authentication errors."""
with patch.object(client.session, 'post') as mock_post:
mock_post.return_value.status_code = 401
with pytest.raises(AuthenticationError):
client.verify("test@example.com")
def test_rate_limit_handling(self, client, mock_response):
"""Test rate limit error handling."""
with patch.object(client.session, 'post') as mock_post:
mock_post.return_value.status_code = 429
mock_post.return_value.headers = {'Retry-After': '30'}
with pytest.raises(RateLimitError) as exc_info:
client.verify("test@example.com")
assert exc_info.value.retry_after == 30
class TestVerificationResult:
"""Tests for VerificationResult model."""
def test_from_dict(self, mock_response):
"""Test creating result from dictionary."""
result = VerificationResult.from_dict(mock_response)
assert result.email == "test@example.com"
assert result.is_valid is True
assert result.domain == "example.com"
def test_is_safe_to_send_valid(self, mock_response):
"""Test safe to send for valid email."""
result = VerificationResult.from_dict(mock_response)
assert result.is_safe_to_send() is True
def test_is_safe_to_send_disposable(self, mock_response):
"""Test safe to send blocks disposable."""
mock_response['is_disposable'] = True
mock_response['risk_score'] = 80
result = VerificationResult.from_dict(mock_response)
assert result.is_safe_to_send() is False
def test_is_safe_to_send_high_risk(self, mock_response):
"""Test safe to send blocks high risk."""
mock_response['risk_score'] = 75
result = VerificationResult.from_dict(mock_response)
assert result.is_safe_to_send() is False
Melhores Práticas de Tratamento de Erros
Implemente tratamento abrangente de erros para confiabilidade em produção:
import logging
from typing import Optional, Callable
from functools import wraps
logger = logging.getLogger(__name__)
def with_verification_fallback(
fallback_value: bool = True,
log_errors: bool = True
):
"""
Decorator to handle verification errors gracefully.
Args:
fallback_value: Value to return on error
log_errors: Whether to log errors
"""
def decorator(func: Callable):
@wraps(func)
def wrapper(*args, **kwargs):
try:
return func(*args, **kwargs)
except AuthenticationError:
logger.critical("Email verification API authentication failed")
raise # Re-raise auth errors
except RateLimitError as e:
if log_errors:
logger.warning(f"Rate limit exceeded, retry after {e.retry_after}s")
return fallback_value
except Exception as e:
if log_errors:
logger.error(f"Email verification failed: {e}")
return fallback_value
return wrapper
return decorator
class SafeEmailVerifier:
"""
Wrapper that provides safe verification with fallbacks.
"""
def __init__(
self,
client: EmailVerificationClient,
strict_mode: bool = False,
default_result: Optional[VerificationResult] = None
):
self.client = client
self.strict_mode = strict_mode
self.default_result = default_result or self._create_default_result()
def verify(self, email: str) -> VerificationResult:
"""
Verify email with graceful error handling.
In non-strict mode, returns a permissive default on errors.
In strict mode, propagates errors.
"""
try:
return self.client.verify(email)
except AuthenticationError:
# Always propagate auth errors
raise
except (RateLimitError, Exception) as e:
logger.error(f"Verification error for {email}: {e}")
if self.strict_mode:
raise
# Return permissive default
result = self._create_default_result()
result.email = email
return result
def _create_default_result(self) -> VerificationResult:
"""Create a permissive default result."""
return VerificationResult(
email="",
is_valid=True,
is_deliverable=True,
is_disposable=False,
is_role_based=False,
is_catch_all=False,
is_free_provider=False,
risk_score=0,
domain="",
mx_records=[],
smtp_check=True,
verification_time_ms=0
)
Monitoramento e Registro
Implemente monitoramento adequado para implantações em produção:
import time
import logging
from dataclasses import dataclass, field
from typing import Dict, List
from datetime import datetime, timedelta
from collections import defaultdict
@dataclass
class VerificationMetrics:
"""Track verification metrics for monitoring."""
total_verifications: int = 0
successful_verifications: int = 0
failed_verifications: int = 0
total_response_time_ms: int = 0
errors_by_type: Dict[str, int] = field(default_factory=lambda: defaultdict(int))
results_by_status: Dict[str, int] = field(default_factory=lambda: defaultdict(int))
hourly_counts: Dict[str, int] = field(default_factory=lambda: defaultdict(int))
@property
def success_rate(self) -> float:
if self.total_verifications == 0:
return 0.0
return self.successful_verifications / self.total_verifications * 100
@property
def avg_response_time_ms(self) -> float:
if self.successful_verifications == 0:
return 0.0
return self.total_response_time_ms / self.successful_verifications
def record_success(self, result: VerificationResult):
"""Record a successful verification."""
self.total_verifications += 1
self.successful_verifications += 1
self.total_response_time_ms += result.verification_time_ms
# Track status distribution
if result.is_deliverable:
self.results_by_status['deliverable'] += 1
if result.is_disposable:
self.results_by_status['disposable'] += 1
if result.is_catch_all:
self.results_by_status['catch_all'] += 1
# Track hourly usage
hour_key = datetime.now().strftime('%Y-%m-%d-%H')
self.hourly_counts[hour_key] += 1
def record_error(self, error_type: str):
"""Record a verification error."""
self.total_verifications += 1
self.failed_verifications += 1
self.errors_by_type[error_type] += 1
def get_summary(self) -> dict:
"""Get metrics summary."""
return {
'total_verifications': self.total_verifications,
'success_rate': f"{self.success_rate:.1f}%",
'avg_response_time_ms': f"{self.avg_response_time_ms:.0f}",
'errors_by_type': dict(self.errors_by_type),
'results_distribution': dict(self.results_by_status)
}
class MonitoredEmailVerificationClient(EmailVerificationClient):
"""Client with built-in monitoring and metrics."""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.metrics = VerificationMetrics()
self.logger = logging.getLogger(f"{__name__}.{self.__class__.__name__}")
def verify(self, email: str) -> VerificationResult:
"""Verify with metrics tracking."""
start_time = time.time()
try:
result = super().verify(email)
self.metrics.record_success(result)
# Log verification details
self.logger.info(
"email_verification",
extra={
'email_domain': result.domain,
'is_valid': result.is_valid,
'is_deliverable': result.is_deliverable,
'is_disposable': result.is_disposable,
'risk_score': result.risk_score,
'response_time_ms': result.verification_time_ms
}
)
return result
except Exception as e:
error_type = type(e).__name__
self.metrics.record_error(error_type)
self.logger.error(
"email_verification_error",
extra={
'email_domain': email.split('@')[-1] if '@' in email else 'unknown',
'error_type': error_type,
'error_message': str(e),
'duration_ms': int((time.time() - start_time) * 1000)
}
)
raise
Conclusão
Integrar a API de verificação de email BillionVerify com Python permite que você construa validação robusta de email em qualquer aplicação. Os padrões e exemplos neste guia fornecem uma base sólida para uso em produção.
Principais conclusões para integração bem-sucedida com Python:
Use uma classe de cliente estruturada com tratamento adequado de erros, lógica de repetição e pool de conexões para confiabilidade
Implemente cache para reduzir chamadas de API e melhorar tempos de resposta para endereços verificados com frequência
Escolha a estratégia de processamento correta com base no seu volume: sequencial para listas pequenas, threads concorrentes para volumes médios e API em lote para listas grandes
Aproveite async/await com aiohttp para aplicações de alto rendimento que precisam verificar muitos emails rapidamente
Integre com seu framework usando decoradores, validadores ou padrões de middleware que se encaixam naturalmente com Django, Flask ou outros frameworks Python
Monitore e meça seu uso de verificação com rastreamento de métricas para entender padrões e otimizar custos
Trate erros com elegância com fallbacks que não bloqueiam usuários quando o serviço de verificação está temporariamente indisponível
Comece com a implementação básica do cliente e adicione progressivamente recursos como cache, processamento em lote e monitoramento conforme suas necessidades crescem. O design modular torna fácil personalizar a integração para seus requisitos específicos.
Para implantações em produção, sempre teste completamente com seus padrões esperados de email e volumes, implemente registro adequado para depuração e configure alertas para falhas de autenticação ou taxas de erro incomuns.