unittest使用ddt来实现测试用例参数化、或parameterized实现测试用例参数化，pytest测试用例里面对应的参数可以用 parametrize 实现参数化，今天我们来了解下fixture参数化params

fixture的参数可以解决大量重复代码工作,比如数据库的连接、查询、关闭等.同样可以使用参数化来测试多条数据用例。

fixture源码：

传入参数scope，params，autouse，ids，name

def fixture(scope="function", params=None, autouse=False, ids=None, name=None):"""Decorator to mark a fixture factory function.This decorator can be used, with or without parameters, to define afixture function.The name of the fixture function can later be referenced to cause itsinvocation ahead of running tests: testmodules or classes can use the ``pytest.mark.usefixtures(fixturename)``marker.Test functions can directly use fixture names as inputarguments in which case the fixture instance returned from the fixturefunction will be injected.Fixtures can provide their values to test functions using ``return`` or ``yield``statements. When using ``yield`` the code block after the ``yield`` statement is executedas teardown code regardless of the test outcome, and must yield exactly once.:arg scope: the scope for which this fixture is shared, one of``"function"`` (default), ``"class"``, ``"module"``,``"package"`` or ``"session"``.``"package"`` is considered **experimental** at this time.:arg params: an optional list of parameters which will cause multipleinvocations of the fixture function and all of the testsusing it.The current parameter is available in ``request.param``.:arg autouse: if True, the fixture func is activated for all tests thatcan see it.  If False (the default) then an explicitreference is needed to activate the fixture.:arg ids: list of string ids each corresponding to the paramsso that they are part of the test id. If no ids are providedthey will be generated automatically from the params.:arg name: the name of the fixture. This defaults to the name of thedecorated function. If a fixture is used in the same module inwhich it is defined, the function name of the fixture will beshadowed by the function arg that requests the fixture; one wayto resolve this is to name the decorated function``fixture_<fixturename>`` and then use``@pytest.fixture(name='<fixturename>')``."""if callable(scope) and params is None and autouse is False:# direct decorationreturn FixtureFunctionMarker("function", params, autouse, name=name)(scope)if params is not None and not isinstance(params, (list, tuple)):params = list(params)return FixtureFunctionMarker(scope, params, autouse, ids=ids, name=name)

params 参数：一个可选的参数列表，它将导致多次调用fixture函数和使用它的所有测试，获取当前参数可以使用request.param，request 是pytest的内置 fixture ，主要用于传递参数

1、获取账号密码案例：

import pytestdata = [("username1", "password1"), ("username2", "password2")]
# data = (("username1", "password1"), ("username2", "password2"))
# data = [["username1", "password1"], ["username2", "password2"]]@pytest.fixture(scope = "function", params = data)
def get_data(request):print(request.param)return request.paramdef test_login(get_data):print("账号：%s"%get_data[0],"密码：%s"%get_data[1])if __name__ == '__main__':pytest.main(["-s", "test_C_01.py"])test_C_01.py ('username1', 'password1')
账号：username1 密码：password1
.('username2', 'password2')
账号：username2 密码：password2
.============================== 2 passed in 0.08s ==============================Process finished with exit code 0

2、前置准备后置清理案例：

import pytest
# 封装删除用户sql
def delete_user(user):sql = "delete from user where mobile = '%s'"%userprint("删除用户sql:%s"%sql)
# 测试数据
mobile_data = ["18200000000", "18300000000"]@pytest.fixture(scope="function", params=mobile_data)
def users(request):'''注册用户参数化'''# 前置操作delete_user(request.param)yield request.param# 后置操作delete_user(request.param)def test_register(users):print("注册用户：%s"%users)if __name__ == '__main__':pytest.main(["-s", "test_C_01.py"])test_C_01.py 删除用户sql:delete from user where mobile = '18200000000'
注册用户：18200000000
.删除用户sql:delete from user where mobile = '18200000000'
删除用户sql:delete from user where mobile = '18300000000'
注册用户：18300000000
.删除用户sql:delete from user where mobile = '18300000000'============================== 2 passed in 0.12s ==============================Process finished with exit code 0