Python 中异常处理库 merry 的用法

def process(num1, num2, file):
 result = num1 / num2
 with open(file, 'w', encoding='utf-8') as f:
 f.write(str(result))

process(1, 2, 'result/result.txt')
process(1, 0, 'result.txt')
process(1, [2], 'result.txt')

def process(num1, num2, file):
 try:
 result = num1 / num2
 with open(file, 'w', encoding='utf-8') as f:
 f.write(str(result))
 except ZeroDivisionError:
 print(f'{num2} can not be zero')
 except FileNotFoundError:
 print(f'file {file} not found')
 except Exception as e:
 print(f'exception, {e.args}')

pip3 install merry

from merry import Merry

merry = Merry()
merry.logger.disabled = True

@merry._try
def process(num1, num2, file):
 result = num1 / num2
 with open(file, 'w', encoding='utf-8') as f:
 f.write(str(result))

@merry._except(ZeroDivisionError)
def process_zero_division_error(e):
 print('zero_division_error', e)

@merry._except(FileNotFoundError)
def process_file_not_found_error(e):
 print('file_not_found_error', e)

@merry._except(Exception)
def process_exception(e):
 print('exception', type(e), e)

if __name__ == '__main__':
 process(1, 2, 'result/result.txt')
 process(1, 0, 'result.txt')
 process(1, 2, 'result.txt')
 process(1, [1], 'result.txt')

file_not_found_error [Errno 2] No such file or directory: 'result/result.txt'
zero_division_error division by zero
exception <class 'TypeError'> unsupported operand type(s) for /: 'int' and 'list'

import requests
from merry import Merry
from requests import ConnectTimeout

merry = Merry()
merry.logger.disabled = True
catch = merry._try

class BaseClass(object):

 @staticmethod
 @merry._except(ZeroDivisionError)
 def process_zero_division_error(e):
 print('zero_division_error', e)

 @staticmethod
 @merry._except(FileNotFoundError)
 def process_file_not_found_error(e):
 print('file_not_found_error', e)

 @staticmethod
 @merry._except(Exception)
 def process_exception(e):
 print('exception', type(e), e)

 @staticmethod
 @merry._except(ConnectTimeout)
 def process_connect_timeout(e):
 print('connect_timeout', e)

class Calculator(BaseClass):

 @catch
 def process(self, num1, num2, file):
 result = num1 / num2
 with open(file, 'w', encoding='utf-8') as f:
 f.write(str(result))

class Fetcher(BaseClass):

 @catch
 def process(self, url):
 response = requests.get(url, timeout=1)
 if response.status_code == 200:
 print(response.text)

if __name__ == '__main__':
 c = Calculator()
 c.process(1, 0, 'result.txt')

 f = Fetcher()
 f.process('http://notfound.com')

zero_division_error division by zero
connect_timeout HTTPConnectionPool(host='notfound.com', port=80): Max retries exceeded with url: / (Caused by ConnectTimeoutError(<urllib3.connection.HTTPConnection object at 0x10d5b9310>, 'Connection to notfound.com timed out. (connect timeout=1)'))

@merry._try
def app_logic():
 db = open_database()
 merry.g.database = db  # save it in the error context just in case
 # do database stuff here

@merry._except(Exception)
def catch_all():
 db = getattr(merry.g, 'database', None)
 if db is not None and is_database_open(db):
 close_database(db)
 print('Unexpected error, quitting')
 sys.exit(1)

from functools import wraps
import inspect
import logging

getargspec = None
if getattr(inspect, 'getfullargspec', None):
 getargspec = inspect.getfullargspec
else:
 # this one is deprecated in Python 3, but available in Python 2
 getargspec = inspect.getargspec

class _Namespace:
 pass

class Merry(object):
 def __init__(self, logger_name='merry', debug=False):
 self.logger = logging.getLogger(logger_name)
 self.g = _Namespace()
 self.debug = debug
 self.except_ = {}
 self.force_debug = []
 self.force_handle = []
 self.else_ = None
 self.finally_ = None

 def _try(self, f):
 @wraps(f)
 def wrapper(*args, **kwargs):
 ret = None
 try:
 ret = f(*args, **kwargs)

 # note that if the function returned something, the else clause
 # will be skipped. This is a similar behavior to a normal
 # try/except/else block.
 if ret is not None:
 return ret
 except Exception as e:
 # find the best handler for this exception
 handler = None
 for c in self.except_.keys():
 if isinstance(e, c):
 if handler is None or issubclass(c, handler):
 handler = c

 # if we don't have any handler, we let the exception bubble up
 if handler is None:
 raise e

 # log exception
 self.logger.exception('[merry] Exception caught')

 # if in debug mode, then bubble up to let a debugger handle
 debug = self.debug
 if handler in self.force_debug:
 debug = True
 elif handler in self.force_handle:
 debug = False
 if debug:
 raise e

 # invoke handler
 if len(getargspec(self.except_[handler])[0]) == 0:
 return self.except_[handler]()
 else:
 return self.except_[handler](e)
 else:
 # if we have an else handler, call it now
 if self.else_ is not None:
 return self.else_()
 finally:
 # if we have a finally handler, call it now
 if self.finally_ is not None:
 alt_ret = self.finally_()
 if alt_ret is not None:
 ret = alt_ret
 return ret
 return wrapper

 def _except(self, *args, **kwargs):
 def decorator(f):
 for e in args:
 self.except_[e] = f
 d = kwargs.get('debug', None)
 if d:
 self.force_debug.append(e)
 elif d is not None:
 self.force_handle.append(e)
 return f
 return decorator

 def _else(self, f):
 self.else_ = f
 return f

 def _finally(self, f):
 self.finally_ = f
 return f

handler = None
for c in self.except_.keys():
 if isinstance(e, c):
 if handler is None or issubclass(c, handler):
 handler = c