simple Python profiler

simple_profiler.py

"""
$ python -i simple_profiler.py
>>> mark()
2015-09-23 20:49:30.993140: Starting profiler [default]
>>> mark('before crazy stuff')
2015-09-23 20:49:34.855766: Profiler [default], mark #1 (before crazy stuff): took 3.862e+00s
>>> mark('after crazy stuff')
2015-09-23 20:49:40.047713: Profiler [default], mark #2 (after crazy stuff): took 5.192e+00s
>>> mark()
2015-09-23 20:49:46.805728: Profiler [default], mark #3: took 6.758e+00s
"""
from __future__ import print_function
from datetime import datetime
from itertools import count
import time


def create_profiler(name):
    print('{}: Starting profiler {}'.format(datetime.now(), name))
    for i in count(1):
        start_time = time.time()
        mark = yield
        end_time = time.time()
        if mark is None:
            mark = ''
        else:
            mark = ' ({})'.format(mark)
        print('{}: Profiler {}, mark #{}{}: took {:.3e}s'.format(
            datetime.now(), name, i, mark, end_time - start_time))


default_profiler = create_profiler('[default]')


def mark(name=None):
    default_profiler.send(name)


class Profiler(object):
    def __init__(self, name):
        self._profiler = create_profiler(name)
        next(self._profiler)

    def mark(self, name=None):
        self._profiler.send(name)