Outline for a logger using with statements, aimed at spreadsheets.

outline_for_spreadsheet_logging.py

from contextlib import contextmanager
import Queue

import threading
import collections

class Cursor(object):
    def __init__(self, worksheet):
        self.worksheet = worksheet
        self.col = 0
        self.row = 0
    

def cursor_logger(cursor):
    def f(msg):
        print '{worksheet} Row#{row} Column#{col} {msg}'.format(msg=msg, col=cursor.col, row=cursor.row, worksheet=cursor.worksheet)
    return f
    
def template_logger(template):
    def f(msg):
        print template.format(msg=msg)
    return f

def default_log(msg):
    print msg
    
class ContextualLogger(object):
    loggers = collections.defaultdict(list)
    
    @classmethod
    @contextmanager
    def log_mgr(cls, logger):
        thread = threading.current_thread()
        
        cls.loggers[thread].append(logger)
        yield logger
        
        try:
            cls.loggers[thread].pop()
        except IndexError:
            del cls.loggers[thread]
            
        
    @classmethod
    def get_logger(cls):
        thread = threading.current_thread()
        loggers = cls.loggers[thread]
        if loggers:
            return loggers[-1]
        else:
            return default_log
        return logger
        
def log(msg):
    logger = ContextualLogger.get_logger()
    logger(msg)

#log('hello')
cursor1 = Cursor('Workbook 1')
cursor2 = Cursor('Workbook 2')
log('hello Z')
with ContextualLogger.log_mgr(cursor_logger(cursor1)):
    log('hello cursor1')
    cursor1.row += 1
    log('hello cursor1')
    with ContextualLogger.log_mgr(cursor_logger(cursor2)):
        log('hello cursor2')
    
    log('hello cursor1')
    log('hello cursor1')
    
log('hello D')