use-breadcrumbs 0.1

breadcrumbs: keep track of what is going on

This library started with a rather simple objective in mind: keep track of a sequence of transforming step.

It is extremely easy:

>>> import breadcrumbs as bc
>>> crumb = bc.Crumb("start")
>>> crumb.info.update(value=35)
>>> crumb.info.update(other_value=70)
>>> print(crumb.info)
{'value': 35, 'other_value': 70}

A Crumb can has an extra and store dependent crumbs using the put_crumb methods.

What is the big deal? You are just writing a dict! True, but the cool thing is that it works a little bit like logging and therefore you use it decoupled across you code:

>>> def func1():
...     bc.info.update(value=35)
>>> def func2():
...     bc.extra.update(other_value=70)
>>> crumb = bc.Crumb("start")
>>> with bc.context(crumb):
...     func2()
...     func1()
>>> print(crumb.info)
{'value': 35}
>>> print(crumb.extra)
{'other_value': 70}

func1 and func2 now nothing about crumb but it just works.

You can also decorate a function to do some things for you automatically.

>>> @bc.aware()
... def func1(x, y):
...     return x + y
>>> crumb = bc.Crumb("start")
>>> with bc.context(crumb):
...     func1(1, 2)
>>> print(crumb.trails)
(Crumb('func1', info={'x': 1, y: '2'}, extra={}))

So in trails you can see that func1 has been called with certain parameters. You can redact some parameters that might be memory intensive or pointless to store.

>>> @bc.aware(redact_params='y')
... def func1(x, y):
...     return x + y
>>> crumb = bc.Crumb("start")
>>> with bc.context(crumb):
...     func1(1, 2)
>>> print(crumb.trails)
(Crumb('func1', info={'x': 1}, extra={}))

To redact more parameters, just pass an iterable.

A useful feature is that a TrailMixin allows you to add object specific notes and teach this to functions.

>>> class MyCoolClass(TrailMixin):
...     # Here goes your cool
...     internal = 10
>>> @bc.aware(trail_param="obj")
... def func1(obj, x, y):
...     return (x + y) * obj.internal
>>> myobj = MyCoolClass()
>>> func1(myobj, 1, 2)
>>> print(myobj.trails)
(Crumb('func1', info={'x': 1, 'y': 2}, extra={}))

$ pip install breadcrumbs