An error handler for functions that are embedded within parallelized functions

EmbeddedFunctionHandler.py

"""
EmbeddedFunctionHandler.py

A class that decorates functions that are embedded/called within
other map|reduce functions. Provides error logging
to log. Type of error and function *args are logged. Useful for Python's
dynamic typing

"""

import sys
import logging
import os

class EmbeddedFunctionHandler(object):

	_log_initialized = False

	def __init__(self, description, max_errors):

		assert self.__class__._log_initialized == True, "log file not initialized"
		self.description = description
		self.max_errors = max_errors

	@classmethod
	def init_log(cls, filename, level):
		if len(logging.getLogger().handlers)>0:
			logging.warning("handler already exists, ignoring log initialization")
			cls._log_initialized = True 
			return
		else:
			logging.basicConfig(filename=filename, level=level)
			cls._log_initialized = True

	def __call__(self, func):
		def inner(*args):
			try:
				return func(*args)
			except Exception as e:
				d = dict(	description=self.description,
							function=func.__name__,
							error=str(type(e)),
							args = str(*args))
				logging.error(d.__repr__())
				self.max_errors -= 1
				print self.max_errors
				if self.max_errors==0:
					msg = "exiting due to max errors on %s"%func.__name__
					logging.debug(msg)
					sys.exit()
				return None
		return inner



# EXAMPLE

if __name__=="__main__":

	EmbeddedFunctionHandler.init_log('file.log', logging.DEBUG)

	MAX_ERRORS = 2
	@EmbeddedFunctionHandler("catch errors adding 1", MAX_ERRORS)
	def add_one(x):
		return x+1

	add_one(2) # prints 3

	add_one("2") # logs error, returns None
	add_one("3") # logs error, returns Non
	add_one("4") # exits

	#### OR #####

	x = [1,2,3,"4","5","6",7]
	map(add_one,x)