how can i run cleanup code only for specific tests with pytest?

Create a fixture with your cleanup code and inject it only into the one test by using the fixture as an argument for your test or by explicitly marking the test with the pytest.mark.usefixtures decorator.

import pytest

@pytest.fixture
def my_cleanup_fixture():
   # Startup code
   ...
   yield
# Cleanup code
   ...

   @pytest.mark.usefixtures('my_cleanup_fixture')
def test_with_special_cleanup():
   pass

Suggestion : 2

Create a fixture with your cleanup code anycodings_python and inject it only into the one test by anycodings_python using the fixture as an argument for anycodings_python your test or by explicitly marking the anycodings_python test with the pytest.mark.usefixtures anycodings_python decorator.,my_cleanup_fixture has scope function by anycodings_python default, so the startup and cleanup code anycodings_python will run for each function it is anycodings_python injected.,I can just put cleanup code at the end of anycodings_python the test. But if test fails then cleanup anycodings_python wont be done.,With pytest is there a way to run cleanup anycodings_python code on a specific test function/method anycodings_python alone. I know we can do this to run for each anycodings_python test function. But here I want to place some anycodings_python cleanup logic specific to a single test anycodings_python function.

import pytest

@pytest.fixture
def my_cleanup_fixture():
   # Startup code
   ...
   yield
# Cleanup code
   ...

   @pytest.mark.usefixtures('my_cleanup_fixture')
def test_with_special_cleanup():
   pass

Suggestion : 3

“Yield” fixtures yield instead of return. With these fixtures, we can run some code and pass an object back to the requesting fixture/test, just like with the other fixtures. The only differences are:,A fixture can also request any other fixture, no matter where it’s defined, so long as the test requesting them can see all fixtures involved.,Due to the usefixtures marker, the cleandir fixture will be required for the execution of each test method, just as if you specified a “cleandir” function argument to each of them. Let’s run it to verify our fixture is activated and the tests pass:,Once pytest figures out a linear order for the fixtures, it will run each one up until it returns or yields, and then move on to the next fixture in the list to do the same thing.

import pytest

class Fruit:
   def __init__(self, name):
   self.name = name

def __eq__(self, other):
   return self.name == other.name

@pytest.fixture
def my_fruit():
   return Fruit("apple")

@pytest.fixture
def fruit_basket(my_fruit):
   return [Fruit("banana"), my_fruit]

def test_my_fruit_in_basket(my_fruit, fruit_basket):
   assert my_fruit in fruit_basket

import pytest

class Fruit:
   def __init__(self, name):
   self.name = name
self.cubed = False

def cube(self):
   self.cubed = True

class FruitSalad:
   def __init__(self, * fruit_bowl):
   self.fruit = fruit_bowl
self._cube_fruit()

def _cube_fruit(self):
   for fruit in self.fruit:
   fruit.cube()

# Arrange
@pytest.fixture
def fruit_bowl():
   return [Fruit("apple"), Fruit("banana")]

def test_fruit_salad(fruit_bowl):
   # Act
fruit_salad = FruitSalad( * fruit_bowl)

# Assert
assert all(fruit.cubed
   for fruit in fruit_salad.fruit)

def fruit_bowl():
   return [Fruit("apple"), Fruit("banana")]

def test_fruit_salad(fruit_bowl):
   # Act
fruit_salad = FruitSalad( * fruit_bowl)

# Assert
assert all(fruit.cubed
   for fruit in fruit_salad.fruit)

# Arrange
bowl = fruit_bowl()
test_fruit_salad(fruit_bowl = bowl)

# contents of test_append.py
import pytest

# Arrange
@pytest.fixture
def first_entry():
   return "a"

# Arrange
@pytest.fixture
def order(first_entry):
   return [first_entry]

def test_string(order):
   # Act
order.append("b")

# Assert
assert order == ["a", "b"]

def first_entry():
   return "a"

def order(first_entry):
   return [first_entry]

def test_string(order):
   # Act
order.append("b")

# Assert
assert order == ["a", "b"]

entry = first_entry()
the_list = order(first_entry = entry)
test_string(order = the_list)

# contents of test_append.py
import pytest

# Arrange
@pytest.fixture
def first_entry():
   return "a"

# Arrange
@pytest.fixture
def order(first_entry):
   return [first_entry]

def test_string(order):
   # Act
order.append("b")

# Assert
assert order == ["a", "b"]

def test_int(order):
   # Act
order.append(2)

# Assert
assert order == ["a", 2]

Suggestion : 4

Jan 25, 2020 , Jan 26, 2020 , Jan 28, 2020 , Released: Jan 28, 2020

pytest_cleanup generates 3 files. These contain the minimal boilerplate required in your test (or current) directory:

2020 - 01 - 25 15: 36: 34.614 | DEBUG | pytest_cleanup.constants: get_test_dir: 18 - Will place test_pytestcleanup_cases.py under / app / test
2020 - 01 - 25 15: 36: 34.614 | INFO | pytest_cleanup.recorder: __init__: 252 - creating instance of recorder
2020 - 01 - 25 15: 36: 34.692 | DEBUG | pytest_cleanup.recorder: save_example_scripts: 159 - Saving example scripts(test_pytestcleanup_cases.py, conftest - pytest - cleanup - runtime.py, conftest - pytest - cleanup - record.py) under test

This will have the following 2 tests:

import pytest

from pytest_cleanup.common
import assert_return_values

def test_pytest_cleanup_sync_test_cases(fn, args, kwargs, expected):
   ""
"See test/test-data directory for test cases"
""
actual = fn( * args, ** kwargs)
assert_return_values(actual, expected)

@pytest.mark.asyncio
async def test_pytest_cleanup_async_test_cases(fn, args, kwargs, expected):
   ""
"See test/test-data directory for test cases.
support
for asyncio in pytest may be enabled by installing pytest - asyncio ""
"
actual = await fn( * args, ** kwargs)
assert_return_values(actual, expected)

The latter will be parametrized with the data files that will be generated later under $your_test_directory/test-data. This is achieved with snippet found with the also generated: conftest-pytest-cleanup-runtime.py (rename it to conftest.py or merge it with your existing conftest.py so that pytest can load it):

def pytest_generate_tests(metafunc):
   from pytest_cleanup
import parametrize_stg_tests

parametrize_stg_tests(metafunc)

pytest_cleanup can also be used as a library for more flexibility. Otherwise, it's only needed as a test dependency.

from pytest_cleanup
import Recorder

with Recorder():
   your_custom_code_here()

The botostubs (by yours truly) went from 0 to 71% adopting pytest_cleanup:

--Docs: https: //docs.pytest.org/en/latest/warnings.html

   -- -- -- -- --coverage: platform linux, python 3.6 .10 - final - 0-- -- -- -- -- -
   Name Stmts Miss Cover Missing
   -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -
   main.py 208 60 71 % 93, 133, 161, 179 - 184, 191, 199 - 210, 214 - 248, 296 - 297, 305 - 310, 314 - 316, 320 - 322, 326

Suggestion : 5

How do I create and cleanup the data I need to test the code?,How do I create and cleanup the data I need to test the code? ,These setup and teardown behaviors are needed when test fixtures must be created. A fixture is any environmental state or object that is required for the test to successfully run.,The setup and teardown functions make our test simpler and the teardown function is guaranteed to be run even if an exception happens in our test. In addition, the setup and teardown functions will be automatically called for every test in a given file so that each begins and ends with clean state.

import os

from mod
import f

def f_setup():
   # The f_setup()
function tests ensure that neither the yes.txt nor the
# no.txt files exist.
files = os.listdir('.')
if 'no.txt' in files:
   os.remove('no.txt')
if 'yes.txt' in files:
   os.remove('yes.txt')

def f_teardown():
   # The f_teardown()
function removes the yes.txt file,
   if it was created.
files = os.listdir('.')
if 'yes.txt' in files:
   os.remove('yes.txt')

def test_f():
   # The first action of test_f() is to make sure the file system is clean.
f_setup()
exp = 42
f()
with open('yes.txt', 'r') as fhandle:
   obs = int(fhandle.read())
assert obs == exp
# The last action of test_f() is to clean up after itself.
f_teardown()

import os

from mod
import f

def setup_function(func):
   # The setup_function()
function tests ensure that neither the yes.txt nor the
# no.txt files exist.
files = os.listdir('.')
if 'no.txt' in files:
   os.remove('no.txt')
if 'yes.txt' in files:
   os.remove('yes.txt')

def teardown_function(func):
   # The f_teardown()
function removes the yes.txt file,
   if it was created.
files = os.listdir('.')
if 'yes.txt' in files:
   os.remove('yes.txt')

def test_f():
   exp = 42
f()
with open('yes.txt', 'r') as fhandle:
   obs = int(fhandle.read())
assert obs == exp

from mod
import f

def test_f(tmpdir):
   exp = 42
f(tmpdir)
with open(tmpdir.join('yes.txt'), 'r') as fhandle:
   obs = int(fhandle.read())
assert obs == exp

import os.path

from mod
import f

def test_f(tmpdir):
   exp = 42
f(tmpdir)
with open(tmpdir.join('yes.txt'), 'r') as fhandle:
   obs = int(fhandle.read())
assert obs == exp

def test_f_with_no(tmpdir):
   with open(tmpdir.join('no.txt'), 'x'):
   pass
f(tmpdir)
assert not os.path.exists(tmpdir.join('yes.txt'))

@something
def something_else():
   pass

import os.path

import pytest

from mod
import f

@pytest.fixture
def no_txt_dir(tmpdir):
   with open(tmpdir.join('no.txt'), 'x'):
   pass
return tmpdir

def test_f(tmpdir):
   exp = 42
f(tmpdir)
with open(tmpdir.join('yes.txt'), 'r') as fhandle:
   obs = int(fhandle.read())
assert obs == exp

def test_f_with_no(no_txt_dir):
   f(no_txt_dir)
assert not os.path.exists(no_txt_dir.join('yes.txt'))

Suggestion : 6

Pytest has two nice features: parametrization and fixtures. They serve completely different purposes, but you can use fixtures to do parametrization.,In this example fixture1 is called at the moment of execution of test_add. The return value of fixture1 is passed into test_add as an argument with a name fixture1. There are many, many nuances to fixtures (e.g. they have scope, they can use yield instead of return to have some cleanup code, etc, etc), but in this post we are looking into one and only one of those features—an argument named params to the pytest.fixture decorator. It is used for parametrization.,A fixture is a function, which is automatically called by Pytest when the name of the argument (argument of the test function or of the another fixture) matches the fixture name. In another words:,A test function can use a fixture by mentioning the fixture name as an input parameter.

A fixture is a function, which is automatically called by Pytest when the name of the argument (argument of the test function or of the another fixture) matches the fixture name. In another words:

@pytest.fixture
def fixture1():
   return "Yes"
def test_add(fixture1):
   assert fixture1 == "Yes"

Let’s create a sample.py file which contains the following code:

import json

class StudentData:
   def __init__(self):
   self.__data = None

def connect(self, data_file):
   with open(data_file) as json_file:
   self.__data = json.load(json_file)

def get_data(self, name):
   for stu in self.__data['students']:
   if stu['name'] == name:
   return stu

Similarly, let’s create the test_sample.py file:

from sample
import StudentData
import pytest

def test_scott_data():
   db = StudentData()
db.connect('data.json')
scott_data = db.get_data('Joseph')
assert scott_data['id'] == 1
assert scott_data['name'] == 'Joseph'
assert scott_data['result'] == 'pass'

def test_mark_data():
   db = StudentData()
db.connect('data.json')
mark_data = db.get_data('Jaden')
assert mark_data['id'] == 2
assert mark_data['name'] == 'Jaden'
assert mark_data['result'] == 'fail'

This method falls under classic xunit-style setup. This section describes a classic and popular way how you can implement fixtures (setup and teardown test state) on a per-module/class/function basis. You must be familiar with this method if you know other testing frameworks like unittest or nose.
So make the changes the in test_sample.py file:

from sample
import StudentData
import pytest
db = None

def setup_module(module):
   print('*****SETUP*****')
global db
db = StudentData()
db.connect('data.json')

def teardown_module(module):
   print('******TEARDOWN******')
db.close()

def test_scott_data():
   scott_data = db.get_data('Joseph')
assert scott_data['id'] == 1
assert scott_data['name'] == 'Joseph'
assert scott_data['result'] == 'pass'

def test_mark_data():
   mark_data = db.get_data('Jaden')
assert mark_data['id'] == 2
assert mark_data['name'] == 'Jaden'
assert mark_data['result'] == 'fail'

Let’s just create a dummy close function for our teardown method in sample.py. The code of sample.py is as follows:

import json

class StudentData:
   def __init__(self):
   self.__data = None

def connect(self, data_file):
   with open(data_file) as json_file:
   self.__data = json.load(json_file)

def get_data(self, name):
   for stu in self.__data['students']:
   if stu['name'] == name:
   return stu

def close(self):
   pass

Suggestion : 7

Each test unit must be fully independent. Each test must be able to run alone, and also within the test suite, regardless of the order that they are called. The implication of this rule is that each test must be loaded with a fresh dataset and may have to do some cleanup afterwards. This is usually handled by setUp() and tearDown() methods.,To mock classes or objects in a module under test, use the patch decorator. In the example below, an external search system is replaced with a mock that always returns the same result (but only for the duration of the test).,Always run the full test suite before a coding session, and run it again after. This will give you more confidence that you did not break anything in the rest of the code.,Learn your tools and learn how to run a single test or a test case. Then, when developing a function inside a module, run this function’s tests frequently, ideally automatically when you save the code.

import unittest

def fun(x):
   return x + 1

class MyTest(unittest.TestCase):
   def test(self):
   self.assertEqual(fun(3), 4)

def square(x):
   ""
"Return the square of x.

>>>
square(2)
4
   >>>
   square(-2)
4
   ""
"

return x * x

if __name__ == '__main__':
   import doctest
doctest.testmod()

$ pip install pytest

# content of test_sample.py
def func(x):
   return x + 1

def test_answer():
   assert func(3) == 5

$ py.test ===
   === === === === === === === === test session starts === === === === === === === === === =
   platform darwin--Python 2.7 .1--pytest - 2.2 .1
collecting...collected 1 items

test_sample.py F

   ===
   === === === === === === === === === === FAILURES === === === === === === === === === === ===
   _______________________________ test_answer ________________________________

def test_answer():
   >
   assert func(3) == 5
E assert 4 == 5
E + where 4 = func(3)

test_sample.py: 5: AssertionError ===
   === === === === === === === = 1 failed in 0.02 seconds === === === === === === === === =

$ pip install hypothesis