Есть два похожих обработчика: AgeHandler1 и AgeHandler2. В первом мы просто вызываем конкретное исключение, чтобы вернуть сообщение об ошибке, во втором — вручную возвращаем сообщение об ошибке. Что Вы думаете об этих двух методах? Какой метод предпочтительнее для большого проекта? Любые другие лучшие практики?
import logging
import os.path
import traceback
from sys import exc_info
from tornado import web, options, ioloop
logger = logging.getLogger(__name__)
class MyAppException(Exception):
def __init__(self, message, code=400, *args, **kwargs):
self.message = message
self.code = code
return super(MyAppException, self).__init__(*args, **kwargs)
def __str__(self):
return self.message
class MyAppBaseHandler(web.RequestHandler):
def handle_exception(self, e):
exc_type, exc_obj, exc_tb = exc_info()
logger.error(''.join([line for line in traceback.format_exception(
exc_type, exc_obj, exc_tb)]))
if isinstance(exc_obj, MyAppException):
self.set_status(exc_obj.code)
self.write({'error': {
'message': u'{exc_obj}'.format(exc_obj=exc_obj.message)}})
else:
self.set_status(500)
fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
self.write({'error': {
'message': u'{exc_obj} in {fname} at {line}'.format(
exc_obj=exc_obj, fname=fname, line=exc_tb.tb_lineno)}})
class AgeHandler1(MyAppBaseHandler):
def get(self):
try:
age = self.get_argument('age')
age = int(age)
if age < 1 or age > 200:
raise MyAppException('Wrong age value.')
self.write('Your age is {age}'.format(age=age))
except Exception as e:
self.handle_exception(e)
class AgeHandler2(MyAppBaseHandler):
def get(self):
age = self.get_argument('age')
age = int(age)
if age < 1 or age > 200:
self.set_status(400)
self.write('Wrong age value.')
return
self.write('Your age is {age}'.format(age=age))
class MyApplication(web.Application):
def __init__(self, **kwargs):
kwargs['handlers'] = [
web.url(r'/age1', AgeHandler1, name='age1'),
web.url(r'/age2', AgeHandler2, name='age2'),
]
kwargs['debug'] = False
super(MyApplication, self).__init__(**kwargs)
if __name__ == '__main__':
options.parse_command_line()
application = MyApplication()
application.listen(5000)
ioloop.IOLoop.instance().start()
Ответы:
"""
http://127.0.0.1:5000/age1
500: {"error": {"message": "HTTP 400: Bad Request (Missing argument age) in app.py at 44"}}
---
http://127.0.0.1:5000/age1?age=10
200: Your age is 10
---
http://127.0.0.1:5000/age1?age=201
400: {"error": {"message": "Wrong age value."}}
---
http://127.0.0.1:5000/age1?age=abc
500: {"error": {"message": "invalid literal for int() with base 10: 'abc' in app.py at 45"}}
http://127.0.0.1:5000/age2
400: <html><title>400: Bad Request</title><body>400: Bad Request</body></html>
---
http://127.0.0.1:5000/age2?age=10
200: Your age is 10
---
http://127.0.0.1:5000/age2?age=201
400: Wrong age value.
---
http://127.0.0.1:5000/age2?age=abc]
500: <html><title>500: Internal Server Error</title><body>500: Internal Server Error</body></html>
"""