当前位置：网站首页>Pytest set (7) - parameterization

Pytest set (7) - parameterization

2022-07-29 07:44:00 【Do it.kiss】

One 、pytest.mark.parametrize()

（1） Grammatical sugar ：

parametrize(argnames, argvalues, indirect=False, ids=None, scope=None, *, _param_mark=None)

（2） Parameter description ：

argnames： Parameter name , Comma separated strings , Represents one or more parameter names . Or a list of parameter strings / Tuples .

If it is a parameter , Use the string of parameter name .

If it's multiple parameters , A comma separated string between multiple parameter names , Or a list of multiple parameter names , Or tuples composed of multiple parameter names .

argvalues： Parameter values , Type is an iteratable object , It corresponds to the parameter name one by one .

If argnames For a parameter , be argvalues Is a list of values .

If argnames For multiple parameters , be argvalues Must be a list of nested tuples , The element value of each tuple corresponds to the parameter name one by one .

indirect： Parameter name list （ Subset of parameter names ） Or boolean values .

indirect Generally speaking, it is related to Pytest Of fixture,request.param Use a combination of

When indrect =True when ,argnames The parameter name is fixture Function name of fixture ,argvalues Is the parameter passed to the fixture function .

ids： Mark the execution name of the parameterized test case , Automatically generated by default , Use "-" Connect .

scope： Parameter range .

（3） Source code ：

def parametrize(
        self,
        argnames: Union[str, List[str], Tuple[str, ...]],
        argvalues: Iterable[Union[ParameterSet, Sequence[object], object]],
        indirect: Union[bool, Sequence[str]] = False,
        ids: Optional[
            Union[Iterable[Optional[object]], Callable[[Any], Optional[object]]]
        ] = None,
        scope: "Optional[_ScopeName]" = None,
        *,
        _param_mark: Optional[Mark] = None,
    ) -> None:
        """Add new invocations to the underlying test function using the list
        of argvalues for the given argnames. Parametrization is performed
        during the collection phase. If you need to setup expensive resources
        see about setting indirect to do it rather than at test setup time.

        Can be called multiple times, in which case each call parametrizes all
        previous parametrizations, e.g.

        ::

            unparametrized:         t
            parametrize ["x", "y"]: t[x], t[y]
            parametrize [1, 2]:     t[x-1], t[x-2], t[y-1], t[y-2]

        :param argnames:
            A comma-separated string denoting one or more argument names, or
            a list/tuple of argument strings.

        :param argvalues:
            The list of argvalues determines how often a test is invoked with
            different argument values.

            If only one argname was specified argvalues is a list of values.
            If N argnames were specified, argvalues must be a list of
            N-tuples, where each tuple-element specifies a value for its
            respective argname.

        :param indirect:
            A list of arguments' names (subset of argnames) or a boolean.
            If True the list contains all names from the argnames. Each
            argvalue corresponding to an argname in this list will
            be passed as request.param to its respective argname fixture
            function so that it can perform more expensive setups during the
            setup phase of a test rather than at collection time.

        :param ids:
            Sequence of (or generator for) ids for ``argvalues``,
            or a callable to return part of the id for each argvalue.

            With sequences (and generators like ``itertools.count()``) the
            returned ids should be of type ``string``, ``int``, ``float``,
            ``bool``, or ``None``.
            They are mapped to the corresponding index in ``argvalues``.
            ``None`` means to use the auto-generated id.

            If it is a callable it will be called for each entry in
            ``argvalues``, and the return value is used as part of the
            auto-generated id for the whole set (where parts are joined with
            dashes ("-")).
            This is useful to provide more specific ids for certain items, e.g.
            dates.  Returning ``None`` will use an auto-generated id.

            If no ids are provided they will be generated automatically from
            the argvalues.

        :param scope:
            If specified it denotes the scope of the parameters.
            The scope is used for grouping tests by parameter instances.
            It will also override any fixture-function defined scope, allowing
            to set a dynamic scope using test context or configuration.
        """

1、 Single parameter name

newly build test_parametrize.py The documents are as follows ：

import pytest


#  Single parameter name 
@pytest.mark.parametrize('a', [1, 2, 3])
def test_one(a):
    print(a)

Run the command ：ytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
==================================== test session starts ====================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 3 items
test_parametrize.py::test_one[1] 1                PASSED
test_parametrize.py::test_one[2] 2                PASSED
test_parametrize.py::test_one[3] 3                PASSED
==================================== 3 passed in 0.04s ====================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

argnames When the parameter name has only one parameter , Use the string of parameter name ,argvalues Parameter values use a list .

The test case test_one Use decorators parametrize,pytest Every time you run a test case , Parameter name a From the parameter value [1,2,3] Take a value from the to run the sub use case .

2、 Multiple parameter names

modify test_parametrize.py The documents are as follows ：

import pytest


#  Single parameter name 
@pytest.mark.parametrize('a', [1, 2, 3])
def test_one(a):
    print(a)


#  Multiple parameter names 
@pytest.mark.parametrize("a,b", [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')])
# @pytest.mark.parametrize(['a', 'b'], [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')])
# @pytest.mark.parametrize(('a', 'b'), [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')])
def test_two(a, b):
    print(a, b)

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
=================================== test session starts ===================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 6 items
test_parametrize.py::test_one[1] 1                PASSED
test_parametrize.py::test_one[2] 2                PASSED
test_parametrize.py::test_one[3] 3                PASSED
test_parametrize.py::test_two[a1-b1] a1 b1                PASSED
test_parametrize.py::test_two[a2-b2] a2 b2                PASSED
test_parametrize.py::test_two[a3-b3] a3 b3                PASSED
=================================== 6 passed in 0.07s ===================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

argnames When there are multiple parameter names , A comma separated string between multiple parameter names , A list of multiple parameter names , Tuple composed of multiple parameter names , All three of them can be .

argnames When there are multiple parameter names ,argvalues Must be a list of nested tuples , The element value of each tuple corresponds to the parameter name one by one .

ids Parameters , Automatically generated by default , Use "-" Connect .

pytest When it's running ,parametrize Decorative test cases test_two From the parameter value list [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')] Remove from 3 Tuples , function 3 Second test case .

3、indrect =True Fixture parameterization

modify test_parametrize.py The documents are as follows ：

import pytest

#  Fixture parameterization 
@pytest.fixture()
def fixture_demo(request):
    return request.param + 1


lst = [1, 2, 3]


# indirect=True,argnames Pass in the fixture function corresponding to the parameter name as a parameter 
@pytest.mark.parametrize('fixture_demo', lst, indirect=True)
def test_three(fixture_demo):
    print(fixture_demo)

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
================================= test session starts =================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.
1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 3 items
test_parametrize.py::test_three[1] 2                PASSED
test_parametrize.py::test_three[2] 3                PASSED
test_parametrize.py::test_three[3] 4                PASSED
=================================== 3 passed in 0.05s ===================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

When indrect =True when ,argnames The parameter name is fixture Function name of fixture ,argvalues Is the parameter that passes the value to the fixture function .

fixture pytest.fixture(params) It can be used to realize parameterization , When parameterizing, you need to use a parameter request, For reception fixture The result returned , adopt request.param To return the parameter content .

4、 Decoration test class

modify test_parametrize.py The documents are as follows ：

import pytest 


#  Decorating a class needs to pay attention to the consistency of parameters with all test functions in the class 
@pytest.mark.parametrize("a,b", [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')])
class TestClass:
    def test_four(self, a, b):
        print(a, b)

    def test_five(self, a, b):
        print(a + b)

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
=================================== test session starts ===================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.
1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 6 items
test_parametrize.py::TestClass::test_four[a1-b1] a1 b1                PASSED
test_parametrize.py::TestClass::test_four[a2-b2] a2 b2                PASSED
test_parametrize.py::TestClass::test_four[a3-b3] a3 b3                PASSED
test_parametrize.py::TestClass::test_five[a1-b1] a1b1                PASSED
test_parametrize.py::TestClass::test_five[a2-b2] a2b2                PASSED
test_parametrize.py::TestClass::test_five[a3-b3] a3b3                PASSED
=================================== 6 passed in 0.20s ===================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

parametrize Decorative class TestClass All test cases in call parameterization .

5、 Decorative module

modify test_parametrize.py The documents are as follows ：

import pytest

pytestmark = pytest.mark.parametrize("a,b", [('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')])


def test_two(a, b):
    print(a, b)


class TestClass:
    def test_four(self, a, b):
        print(a, b)

    def test_five(self, a, b):
        print(a + b)

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
=================================== test session starts ===================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 9 items
test_parametrize.py::test_two[a1-b1] a1 b1                PASSED
test_parametrize.py::test_two[a2-b2] a2 b2                PASSED
test_parametrize.py::test_two[a3-b3] a3 b3                PASSED
test_parametrize.py::TestClass::test_four[a1-b1] a1 b1                PASSED
test_parametrize.py::TestClass::test_four[a2-b2] a2 b2                PASSED
test_parametrize.py::TestClass::test_four[a3-b3] a3 b3                PASSED
test_parametrize.py::TestClass::test_five[a1-b1] a1b1                PASSED
test_parametrize.py::TestClass::test_five[a2-b2] a2b2                PASSED
test_parametrize.py::TestClass::test_five[a3-b3] a3b3                PASSED
==================================== 9 passed in 0.08s ====================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

Use global variables pytestmark = pytest.mark.parametrize(), All test cases in the module can be parameterized .

6、 Built in mark.xfail, Mark the expected execution failure of the test case in the parameterization

modify test_parametrize.py The documents are as follows ：

import pytest 


#  Built in mark.xfail, Mark the expected execution failure of a single test case in parameterization 
@pytest.mark.parametrize("test_input,expected",
                         [("3+5", 8), ("2+4", 6), pytest.param("6*9", 42, marks=pytest.mark.xfail)])
def test_eval(test_input, expected):
    assert eval(test_input) == expected

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -v
================================== test session starts ==================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 3 items
test_parametrize.py::test_eval[3+5-8] PASSED [ 33%]
test_parametrize.py::test_eval[2+4-6] PASSED [ 66%]
test_parametrize.py::test_eval[6*9-42] XFAIL [100%]
=============================== 2 passed, 1 xfailed in 0.46s ===============================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

xfail The marked test case is expected to fail , Actual execution failed , Then the status is marked XFAIL.

7、 Stack multiple parametrize Decorator

modify test_parametrize.py The documents are as follows ：

import pytest


#  Stack multiple parametrize Decorator , under these circumstances , Every call parameterizes all previous parameterizations .
@pytest.mark.parametrize('a', ['a1', 'a2'])
@pytest.mark.parametrize('b', ['b1', 'b2', 'b3'])
def test_over(a, b):
    print(a, b)

Run the command ：pytest test_parametrize.py -vs

(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>pytest test_parametrize.py -vs
=================================== test session starts ===================================
platform win32 -- Python 3.8.8, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- e:\programs\python\python38\python.exe
cachedir: .pytest_cache
metadata: {'Python': '3.8.8', 'Platform': 'Windows-10-10.0.19041-SP0', 'Packages': {'pytest': '6.2.3', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'html': '3.1.1', 'metadata': '1.11.0', 'rerunfailures': '9.1.1', 'assume': '2.2.0', 'requests-mock': '1.7.0'}, 'JAVA_HOME': 'C:\\Program Files\\Java\\jdk1.8.0_271'}
rootdir: C:\Users\057776\PycharmProjects\pytest-demo\testmark, configfile: pytest.ini
plugins: html-3.1.1, metadata-1.11.0, rerunfailures-9.1.1, assume-2.2.0, requests-mock-1.7.0
collected 6 items
test_parametrize.py::test_over[b1-a1] a1 b1                PASSED
test_parametrize.py::test_over[b1-a2] a2 b1                PASSED
test_parametrize.py::test_over[b2-a1] a1 b2                PASSED
test_parametrize.py::test_over[b2-a2] a2 b2                PASSED
test_parametrize.py::test_over[b3-a1] a1 b3                PASSED
test_parametrize.py::test_over[b3-a2] a2 b3                PASSED
=================================== 6 passed in 0.07s ===================================
(venv) C:\Users\057776\PycharmProjects\pytest-demo\testmark>

explain ：

Stack multiple parametrize Decorator , under these circumstances , Every call parameterizes all previous parameterizations .