behave

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Introduction

behave describes itself as “BDD, Python style”. Behaviour-driven development uses plain-language scenarios, written in Gherkin with Given/When/Then steps, as shared specifications between product, QA and engineering. behave reads .feature files and matches each step to a Python function decorated with @given, @when or @then.

Projects follow a convention: a features/ directory holding feature files, a steps/ subdirectory for step implementations, and an optional environment.py for hooks such as before_all, before_scenario and after_step, often used to start browsers or reset databases. Step patterns can use the parse library’s syntax ({count:d}) or regular expressions, and scenarios support outlines with example tables, backgrounds, tags for selection (--tags=@smoke) and multiple formatters, including pretty, plain, JSON and JUnit XML for CI. The latest release, v1.3.3, was published on 4 September 2025, and the repository remains active with commits in November 2026.

The source code is at behave/behave on GitHub under the BSD-2-Clause licence, with about 3,500 stars; the most recent commit was on 6 November 2026.

Features

1. Gherkin scenarios: Readable specifications shared with non-developers.
2. Python step definitions: Decorated functions with parse or regex patterns.
3. Hooks: Environment hooks for setup and teardown.
4. Tags and formatters: Select scenarios and output JUnit XML or JSON.

Pros

1. Free to use: Open source under the BSD-2-Clause licence, so the core tool costs nothing to use.
2. Actively maintained: The repository had commits as recent as 6 November 2026.
3. Community: About 3,500 GitHub stars.

Cons

1. Separate from pytest: Does not use pytest fixtures; pytest-bdd integrates with pytest instead.
2. BDD overhead: Gherkin adds value only when stakeholders read the scenarios.

Usage and Links (Example)

# features/cart.feature
Feature: Cart
  Scenario: Add an item
    Given an empty cart
    When I add 2 apples
    Then the cart contains 2 items

# features/steps/cart_steps.py
from behave import given, when, then

@given("an empty cart")
def step_empty(context):
    context.cart = []

@when("I add {count:d} apples")
def step_add(context, count):
    context.cart += ["apple"] * count

@then("the cart contains {count:d} items")
def step_check(context, count):
    assert len(context.cart) == count

pip install behave
behave --tags=@smoke --junit

Resources:

• behave website
• GitHub repository

Pricing

behave is free and open source under the BSD-2-Clause licence.

Recommended for?

1. Teams practising BDD in Python with business-readable scenarios.
2. QA teams writing acceptance tests outside pytest.

Conclusion

behave is the classic Python BDD framework, straightforward and well documented, ideal when Gherkin scenarios are a genuine collaboration tool.