TRACE decorator with indent. using standard python logging.

trace.py

import logging
import functools
import traceback

def trace(fn):
    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
        indent = ' ' * len(traceback.extract_stack())
        try:
            logging.debug('{0}entering {1}'.format(indent, fn.__name__))
            return fn(*args, **kwargs)
        except:
            logging.debug('{0}exception in {1}'.format(indent, fn.__name__))
            raise
        else:
            logging.debug('{0}leaving {1}'.format(indent, fn.__name__))

    return wrapper