csvlogging.py

import logging
from logging import handlers
import csv
import io
import time
import os
from datetime import datetime

class CSVFormatter(logging.Formatter):
	def __init__(self):
		super().__init__()
	def format(self, record):
		stringIO = io.StringIO()
		writer = csv.writer(stringIO, quoting=csv.QUOTE_ALL)
		writer.writerow(record.msg)
		record.msg = stringIO.getvalue().strip()
		return super().format(record)

class CouldNotBeReady(Exception):
	pass

class CSVTimedRotatingFileHandler(handlers.TimedRotatingFileHandler):
	def __init__(self, filename, when='D', interval=1, backupCount=0,
                 encoding=None, delay=False, utc=False, atTime=None,
                 errors=None, retryLimit=5, retryInterval=0.5,header="NO HEADER SPECIFIED"):
		self.RETRY_LIMIT = retryLimit
		self._header = header
		self._retryLimit = retryLimit
		self._retryInterval = retryInterval
		self._hasHeader = False
		super().__init__(filename, when, interval, backupCount, encoding, delay, utc, atTime)
		if os.path.getsize(self.baseFilename) == 0:
			writer = csv.writer(self.stream, quoting=csv.QUOTE_ALL)
			writer.writerow(self._header)
		self._hasHeader = True

	def doRollover(self):
		self._hasHeader = False
		self._retryLimit = self.RETRY_LIMIT
		super().doRollover()
		writer = csv.writer(self.stream, quoting=csv.QUOTE_ALL)
		writer.writerow(self._header)
		self._hasHeader = True

	def emit(self, record):
		while self._hasHeader == False:
			if self._retryLimit == 0:
				raise CouldNotBeReady
			time.sleep(self._retryInterval)
			self._retryLimit -= 1
			pass
		super().emit(record)

logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
loggingStreamHandler = CSVTimedRotatingFileHandler(filename="log.csv", header=["time","number"]) #to save to file
loggingStreamHandler.setFormatter(CSVFormatter())
logger.addHandler(loggingStreamHandler)
import random
while True:
	today = str(datetime.now().strftime("%m/%d/%Y, %H:%M:%S"))
	logger.info([today,random.randint(10,100)])
	time.sleep(1)