Metadata-Version: 1.1
Name: measure-it
Version: 0.2
Summary: time and count measurement for iterators
Home-page: http://github.com/wearpants/measure_it
Author: Pete Fein
Author-email: pete@wearpants.org
License: BSD
Description: measure_it
        ==========
        
        `measure_it <http://github.com/wearpants/measure_it>`__ provides timing and counting for iterators.
        
        .. currentmodule:: measure_it
        
        Basic Usage
        ===========
        
        Iterators & generators often encapsulate I/O, number crunching or other
        operations we want to gather metrics for:
        
        >>> from time import sleep
        >>> def math_is_hard(N):
        ...     x = 0
        ...     while x < N:
        ...         sleep(.1)
        ...         yield x * x
        ...         x += 1
        
        Timing iterators is tricky. :func:`measure` and :func:`measure_each` record
        metrics for time and element count for iteratables.
        
        >>> from measure_it import measure, measure_each
        
        Wrap an iterator in :func:`measure` to time how long it takes to consume entirely:
        
        >>> underlying = math_is_hard(5)
        >>> underlying # doctest: +ELLIPSIS
        <generator object math_is_hard at ...>
        >>> _ = measure(underlying)
        >>> squares = list(_)
        5 elements in 0.50 seconds
        
        The wrapped iterator yields the same results as the underlying iterable:
        
        >>> squares
        [0, 1, 4, 9, 16]
        
        The :func:`measure_each` wrapper measures the time taken to produce each item:
        
        >>> _ = measure_each(math_is_hard(5))
        >>> list(_)
        1 elements in 0.10 seconds
        1 elements in 0.10 seconds
        1 elements in 0.10 seconds
        1 elements in 0.10 seconds
        1 elements in 0.10 seconds
        [0, 1, 4, 9, 16]
        
        You can provide a custom name for the metric:
        
        >>> _ = measure(math_is_hard(5), name="bogomips")
        >>> list(_)
        bogomips: 5 elements in 0.50 seconds
        [0, 1, 4, 9, 16]
        
        Decorators
        ==========
        
        If you have a generator function (one that uses `yield`), you can wrap it with a decorator using `.func()`. You can pass the same `name` and `metric` arugments:
        
        >>> @measure_each.func()
        ... def slow(N):
        ...     for i in range(N):
        ...         sleep(.1)
        ...         yield i
        >>> list(slow(3))
        __main__.slow: 1 elements in 0.10 seconds
        __main__.slow: 1 elements in 0.10 seconds
        __main__.slow: 1 elements in 0.10 seconds
        [0, 1, 2]
        
        Decorators work inside classes too. If you don't provide a name, a decent one will be inferred:
        
        >>> class Database(object):
        ...     @measure.func()
        ...     def batch_get(self, ids):
        ...         # you'd actually hit database here
        ...         for i in ids:
        ...             sleep(.1)
        ...             yield {"id":i, "square": i*i}
        >>> database = Database()
        >>> _ = database.batch_get([1, 2, 3, 9000])
        >>> list(_)
        __main__.Database.batch_get: 4 elements in 0.40 seconds
        [{'square': 1, 'id': 1}, {'square': 4, 'id': 2}, {'square': 9, 'id': 3}, {'square': 81000000, 'id': 9000}]
        
        Reducers
        ========
        
        The `measure_reduce` decorator measures functions that consume many items.
        Examples include aggregators or a `batch_save()`:
        
        >>> from measure_it import measure_reduce 
        
        `measure_reduce` is a decorator for functions, *not* iterators:
        
        >>> @measure_reduce()
        ... def sum_squares(L):
        ...     total = 0
        ...     for i in L:
        ...         sleep(.1)
        ...         total += i*i
        ...     return total
        ... 
        >>> sum_squares(range(5))
        5 elements in 0.50 seconds
        30
        
        This works with `*args` functions too:
        
        >>> @measure_reduce()
        ... def sum_squares2(*args):
        ...     total = 0
        ...     for i in args:
        ...         sleep(.1)
        ...         total += i*i
        ...     return total
        ... 
        >>> sum_squares2(*range(5))
        5 elements in 0.50 seconds
        30
        
        And inside classes:
        
        >>> class Database(object):
        ...     @measure_reduce()
        ...     def batch_save(self, rows):
        ...         for r in rows:
        ...             # you'd actually commit to your database here
        ...             sleep(0.1)
        ... 
        ...     @measure_reduce()
        ...     def batch_save2(self, *rows):
        ...         for r in rows:
        ...             # you'd actually commit to your database here
        ...             sleep(0.1)
        ... 
        >>> rows = [{'id':i} for i in range(5)]
        >>> database = Database()
        >>> database.batch_save(rows)
        5 elements in 0.50 seconds
        >>> database.batch_save2(*rows)
        5 elements in 0.50 seconds
        
        Customizing Output
        ==================
        
        By default, metrics are printed to standard out. You can provide your own
        metric recording funtion. It should take three arguments: `count` of items,
        `elapsed` time in seconds, and `name`, which can be None:
        
        >>> def my_metric(name, count, elapsed):
        ...     print("Iterable %s produced %d items in %d milliseconds"%(name, count, int(round(elapsed*1000))))
        ... 
        >>> _ = measure(math_is_hard(5), name="bogomips", metric=my_metric)
        >>> list(_)
        Iterable bogomips produced 5 items in 502 milliseconds
        [0, 1, 4, 9, 16]
        
        If you have `statsd <https://pypi.python.org/pypi/statsd>`__ installed, the
        :func:`statsd_metric` function can be used to record metrics to it. Or write
        your own!
        
        API Documentation
        =================
        
        .. automodule:: measure_it
            :members: measure, measure_each, measure_reduce, print_metric
        
        Changelog
        =========
        
        0.2
        ---
        add `measure_reduce`
        
        0.1
        ---
        Initial release
        
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 3
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
