import logging
from slacker import Slacker
import os


class SlackHandler(logging.Handler):
    def __init__(self, slack_token):
        logging.Handler.__init__(self)
        self.slack = Slacker(slack_token)

    def emit(self, record):
        self.slack.chat.post_message('#leonard', text='ERROR ON {}\n{}'.format(
            'DEBUG' if os.environ.get('BOT_DEBUG', '0') == '1' else 'PRODUCTION @channel',
            record
        ), parse='full')

import logging
from slacker import Slacker
import os


class SlackHandler(logging.Handler):
    def __init__(self, slack_token):
        logging.Handler.__init__(self)
        self.slack = Slacker(slack_token)

    def emit(self, record):
        self.slack.chat.post_message('#leonard', text='ERROR ON {}\n{}'.format(
            'DEBUG' if os.environ.get('BOT_DEBUG', '0') == '1' else 'PRODUCTION',
            record
        ), parse='full')

Update slackhandler.py