cheatsheet utils.py

utils.py

import os
import time
import logging
from functools import update_wrapper


logging.basicConfig(
    level=logging.DEBUG, format='%(asctime)s|%(levelname)s|%(message)s')


def decorator(d):
    "Make function d a decorator: d wraps a function fn."
    def _d(fn):
        return update_wrapper(d(fn), fn)
    update_wrapper(_d, d)
    return _d


@decorator
def timeit(f):
    """time a function, used as decorator"""
    def new_f(*args, **kwargs):
        bt = time.time()
        r = f(*args, **kwargs)
        et = time.time()
        logging.info(f"time spent on {f.__name__}: {et - bt:.2f}s")
        return r
    return new_f


def backup_file(f):
    """
    Back up a file, old_file will be renamed to #old_file.n#, where n is a
    number incremented each time a backup takes place
    """
    if os.path.exists(f):
        dirname = os.path.dirname(f)
        basename = os.path.basename(f)
        count = 1
        rn_to = os.path.join(
            dirname, '#' + basename + '.{0}#'.format(count))
        while os.path.exists(rn_to):
            count += 1
            rn_to = os.path.join(
                dirname, '#' + basename + '.{0}#'.format(count))
        logging.info("Backing up {0} to {1}".format(f, rn_to))
        os.rename(f, rn_to)
        return rn_to