wraptools 1.1

Utilities for wrapping and dispatching functions

Utilities for wrapping and dispatching functions.

Supported Python versions:

• 2.7
• 3.4
• 3.5

pluggable

pluggable will take some decorators and simply apply it. But applied decorators can be purged by purge_pluggable_decorators.

from functools import lru_cache
from wraptools.pluggable import pluggable

@pluggable(
    lru_cache,
)
def get_data():
    """ Some function return data from RDB or so. """

purge_pluggable_decorators is useful on tests.

from wraptools.pluggable import purge_pluggable_decorators

    @purge_pluggable_decorators
    def test__get_data(self):
         always_flesh_data = get_data()

Or it can be also used as a context manager.

with purge_pluggable_decorators():
    always_flesh_data = get_data()

pluggable decorator can be useful for view functions of Web Frameworks, like Django.

@pluggable(
    login_required,
)
def profile_view(request):
    return TemplateResponse(request, "profile.html")

dispatch

dispatch will create function by some condition and functions. Following example means

• When request is authenticated, dashboard function will be called.
• Other cases, landing_page function will be called.

from wraptools.dispatch import dispatch
from wraptools.contrib.django.dispatchers import is_authenticated


def landing_page(request):
    return TemplateResponse(request, "landing.html")


def dashboard(request):
    return TemplateResponse(request, "dashboard.html")


top_view = dispatch(
    (is_authenticated, dashboard),
    default=landing_page,
)

Combine conditions

In this case dispatch is used for Django’s view, but it can be used generic Python functions.

dispatcher functions can be combined and inverted.

• To create and condition, just combine dispatchers by &
• or condition, by |
• not condition, by ~

from wraptools.contrib.django.dispatchers import is_authenticated, method_get

top = dispatch(
    (is_authenticated & method_get, dashboard_get),
    (is_authenticated & (method_post | method_put), dashboard_post),
    (~is_authenticated, landing),
)

Create own dispatcher

Basically dispatcher is just a function to get same arguments with dispatched functions and return bool values.

def is_even(num):
    return num % 2 == 0

def echo(num):
    return num

dispatch(
    (is_even, echo),
    ...
)

But by using dispatcher decorator, your dispatcher functions will be able to be combined and inverted by &, |, or ~

from wraptools.dispatch import dispatcher

dispatcher
def is_even(num):
    return num % 2 == 0

dispatch(
    (~is_even, ...),  # It will be called when the value is odd (not even).
    ...
)

context

context is a decorator which injects additional arguments to wrapped functions. Following example is to separate logic to get user object into get_user context function, and applying it for profile_page view by context decorator.

from wraptools.context import context


def get_user(user_id):
    return get_object_or_404(User, id=user_id)


@context(
    get_user,
)
def profile_page(request, user_id, user):
    return TemplateResponse(request, "profile.html")