Ранее я уже упоминал о другой фишке из ˍˍfutureˍˍ , это оператор деления.
from __future__ import division
Суть проста. Раньше сложность типа данных результата поределялась типом самого сложного операнда.
Например:
int/int => int
int/float => float
В первом случае оба операнда int, значит и результат будет int. Во втором float более сложный тип, поэтому результат будет float.
Если нам требуется получить дробное значение при делении двух int то приходилось форсированно один из операндов конверировать в float.
12/float(5) => float
Но с новой "философией" это не требуется. В Python3 "floor division" заменили на "true division" а старый способ теперь работает через оператор "//".
>>> 3/2
1.5
>>> 3//2
1
То есть теперь деление int на int даёт float если результат не целое число.
В классах теперь доступны методы __floordiv__() и __truediv__() для определения поведения с этими операторами.
Данный переход описан в PEP238.
#pep#2to3#basic
https://code.tutsplus.com/tutorials/behavior-driven-development-in-python--net-26547
Behavior-Driven Development (which we will now refer to as "#BDD") follows on from the ideas and principles introduced in #Test-Driven Development. The key points of writing tests before code really apply to BDD as well. The idea is to not only test your code at the granular level with unit tests, but also test your application end to end, using acceptance tests. We will introduce this style of testing with the use of the Lettuce testing framework.
http://pythonhosted.org/behave/
behave is behaviour-driven development, Python style.
Behavior-driven development (or #BDD) is an agile software development technique that encourages collaboration between developers, #QA and non-technical or business participants in a software project. We have a page further describing this philosophy.
behave uses tests written in a natural language style, backed up by Python code.
Once you’ve installed behave, we recommend reading the
tutorial first and then
feature test setup,
behave API and
related software (things that you can combine with behave)
finally: how to use and configure the behave tool.
https://pypi.python.org/pypi/pytest-bdd
#BDD library for the py.test runner
#pytest-bdd implements a subset of Gherkin language for the automation of the project requirements testing and easier behavioral driven development.
Unlike many other BDD tools it doesn’t require a separate runner and benefits from the power and flexibility of the #pytest. It allows to unify your unit and functional #tests, easier continuous integration server configuration and maximal reuse of the tests setup.
Pytest fixtures written for the #unit_test s can be reused for the setup and actions mentioned in the feature steps with dependency injection, which allows a true BDD just-enough specification of the requirements without maintaining any context object containing the side effects of the Gherkin. imperative declarations.