MJ Helpers

A collection of helper functions and decorators that I occasionally use to get my life in order.

Installation

pip install mj_helpers

profileit

A decorator to profile function calls.

Usage:

from mj_helpers.decorators import profileit

@profileit
def foo():
    return do_stuff()

In a Python shell:

>>> from .foo import foo
>>> foo()
>>> from pstats import Stats
>>> stats = Stats('/tmp/foo.profile')
>>> stats.sort_stats('cumulative').print_stats(50)

Fri Nov 27 08:34:14 2015    /tmp/foo.profile
2 function calls in 0.000 seconds

Ordered by: cumulative time
ncalls  tottime  percall  cumtime  percall filename:lineno(function)
     1    0.000    0.000    0.000    0.000 <ipython-input-8-8f35865ca12d>:1(foo)
     1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

If installed via pip or python setup.py:

mj_stats /tmp/foo.profile /tmp/bar.profile --sorting=cumulative --limit=50

log_function_io

Logging decorator that logs function name, args and kwargs.

In Python:

from mj_helpers.log_decorator import log_function_io

@log_function_io
def foo(bar, spam=None, *args, **kwargs):
    return do_stuff()


class Thing(object):
    pass


class Bar(object):

    @staticmethod
    @log_function_io
    def static_method(spam, eggs='eggs'):
        return True

    @classmethod
    @log_function_io
    def class_method(cls, foo='foo', bar=None):
        return False


    @log_function_io
    def function(self, thing):
        return Thing()

Console:

>>> foo('a', *['first star', 'second star'], **{'something': 'boo'})
2016-02-02 05:04:50,963 - __main__ - DEBUG - [FUN] foo [ARG] bar: 'a', spam: 'first star', something: 'boo' *('second star',)
2016-02-02 05:04:50,963 - __main__ - DEBUG - [FUN] foo [RET] None

>>> Bar.static_method('spam')
2016-02-02 05:09:30,426 - __main__ - DEBUG - [FUN] static_method [ARG] spam: 'spam'
2016-02-02 05:09:30,426 - __main__ - DEBUG - [FUN] static_method [RET] True

>>> Bar.class_method(bar='spam')
2016-02-02 05:11:39,753 - __main__ - DEBUG - [FUN] class_method [ARG] bar: 'spam'
2016-02-02 05:11:39,753 - __main__ - DEBUG - [FUN] class_method [RET] False

>>> Bar().function(thing='spam')
2016-02-02 05:13:01,679 - __main__ - DEBUG - [FUN] function [ARG] thing: 'spam'
2016-02-02 05:13:01,679 - __main__ - DEBUG - [FUN] function [RET] <__main__.Thing object at 0x7f33d8627f90>

cache_it

Caching decorator to assist in caching function calls / returns.

In Python:

from mj_helpers.decorators import cache_it

@cache_it()
def foo(bar, spam=None, *args, **kwargs):
    return do_stuff()

# If using memoize instead of django's cache you can see the cache by:
>>> cache_it._cache
{
    <function foo at 0x7f4419daa848>: {
        "(('a', 'first star', 'second star'), (('something', 'boo'),))":
        (None, 1454391947.614329)
    }
}