Python Behave BDD Framework Overview

Python behave is a much widely used BDD framework these days. In this blog article, you will get to learn behave BDD framework’s features and how to use it to create automation test scripts. Behave is an open source tool which has 62 contributors who are actively developing new features and fixing the issues. Python Behave is a matured BDD framework.

Implementing readable and business friendly automation testing solution is the need of the hour. When your automation test suites gives provision for non-technical people to collaborate, it will be a value add to your product/project. As an automation testing services company, we get lot of inquiries on implementing business friendly test automation solution of late.

Feature Files

behave is considered to be a clone of Cucumber BDD framework. Most of the features of behave is similar to Cucumber. However, there is a provision for additional flexibility in behave framework. Let’s have a look at them one by one. You can execute feature files in the following ways – by providing feature name, feature directory, at last without providing feature details. When you run behave command without feature path, it will search feature files in features directory by default.

Fixtures

Fixtures aka Hooks are used to call Setup & Cleanup code before and after Test Run, Feature, Scenario, and Tag. You needn’t write a separate method for ‘After’ hooks. Both ‘Before’ and ‘After’ hooks can be implemented inside a single method. Let’s look at the below example.

Feature

@launch.browser
Feature: Codoid Website Feature

Scenario: Contact Codoid Team
  Given I am on home page
  When I submit contact us form
  Then I should see Thank You page with a message
  

environment.py

from behave import fixture, use_fixture
from selenium import webdriver

@fixture
def launch_browser(context, timeout=30, **kwargs):
    context.driver = webdriver.Chrome(executable_path='driverschromedriver.exe')
    yield context.driver
    context.driver.quit()

def before_tag(context, tag):
    if tag == "launch.browser":
        the_fixture = use_fixture(launch_browser, context)
  

step_def.py

from behave import given, when, then
from selenium import webdriver

@given('I am on home page')
def step_impl(context):
    context.driver.get("https://codoid.com")
    assert True is True
  

Executing Remaining Steps in a Scenario

By default, scenario execution will be stopped if any of the steps is failed. However, you can override this in behave framework using Hooks and Command line.

Hook

from behave.model import Scenario

def before_all(context):
    userdata = context.config.userdata
    continue_after_failed = userdata.getbool("runner.continue_after_failed_step", False)
    Scenario.continue_after_failed_step = continue_after_failed
  

Command Line

behave -D runner.continue_after_failed_step=true features/
  

Filtering Scenarios and Examples using Tag Value

You can select scenarios and examples using Tag and its value. This feature is helpful when you want to select an example based on the environment value for a tag.

Feature:
  Scenario Outline: Wow
    Given an employee "<name>"

    @use.with_stage=develop
    Examples: Araxas
      | name  | birthyear |
      | Alice |  1985     |
      | Bob   |  1975     |

    @use.with_stage=integration
    Examples:
      | name   | birthyear |
      | Charly |  1995     |
  

In Conclusion

As a test automation services company, we advocate behave BDD framework for creating readable and understandable automation test suite. It is still widely used by the automation community and its contributors are releasing newer versions frequently based on the market need.