Creating step-based tests in Python with alternative execution paths. In this example we want to perform a test which always starts with `step_a` and always ends with `step_d` but in the middle can take either `step_b` and `step_c` either alternative steps. We test if final number is `12` and it can be obtained as `3*4=12` or `2*6=12` and those …

out.txt

$ python -m pytest run.py -vvv
============================= test session starts ==============================
platform darwin -- Python 3.5.3, pytest-4.2.0, py-1.8.0, pluggy-0.12.0 -- /Users/marek/.pyenv/versions/3.5.3/bin/python
cachedir: .pytest_cache
rootdir: /Users/marek/Development/qtl/36a5d4cb5674e14792b03b4f79b89402, inifile:
plugins: steps-1.6.4, timeout-1.3.3, flaky-3.6.1
collected 8 items                                                              

braids_test.py::test_scenario_1[step_a] PASSED                           [ 12%]
braids_test.py::test_scenario_1[step_b] PASSED                           [ 25%]
braids_test.py::test_scenario_1[step_c] PASSED                           [ 37%]
braids_test.py::test_scenario_1[step_d] PASSED                           [ 50%]
braids_test.py::test_scenario_2[step_a] PASSED                           [ 62%]
braids_test.py::test_scenario_2[step_b_alt] PASSED                       [ 75%]
braids_test.py::test_scenario_2[step_c_alt] PASSED                       [ 87%]
braids_test.py::test_scenario_2[step_d] PASSED                           [100%]

=========================== 8 passed in 0.08 seconds ===========================

run.py

import pytest
from pytest_steps import test_steps

def step_a(steps_data):
    steps_data.a = 12

def step_b(steps_data):
    steps_data.b = 4

def step_b_alt(steps_data):
    steps_data.b = 2

def step_c(steps_data):
    steps_data.c = 3

def step_c_alt(steps_data):
    steps_data.c = 6

def step_d(steps_data):
    assert steps_data.b*steps_data.c == steps_data.a

@test_steps(step_a, step_b, step_c, step_d)
def test_scenario_1(test_step, steps_data):
    test_step(steps_data)

@test_steps(step_a, step_b_alt, step_c_alt, step_d, steps_data_holder_name='steps_data_alt')
def test_scenario_2(test_step, steps_data_alt):
    test_step(steps_data_alt)