一个可以查看所有收集的测试的会话固定装置

一个会话范围的固定装置有效地访问所有收集的测试项。这是一个固定装置函数的示例，它遍历所有收集的测试并查看它们的测试类是否定义了 callme 方法并调用它

# content of conftest.py

import pytest


@pytest.fixture(scope="session", autouse=True)
def callattr_ahead_of_alltests(request):
    print("callattr_ahead_of_alltests called")
    seen = {None}
    session = request.node
    for item in session.items:
        cls = item.getparent(pytest.Class)
        if cls not in seen:
            if hasattr(cls.obj, "callme"):
                cls.obj.callme()
            seen.add(cls)

测试类现在可以定义一个 callme 方法，该方法将在运行任何测试之前被调用

# content of test_module.py


class TestHello:
    @classmethod
    def callme(cls):
        print("callme called!")

    def test_method1(self):
        print("test_method1 called")

    def test_method2(self):
        print("test_method2 called")


class TestOther:
    @classmethod
    def callme(cls):
        print("callme other called")

    def test_other(self):
        print("test other")


# works with unittest as well ...
import unittest


class SomeTest(unittest.TestCase):
    @classmethod
    def callme(self):
        print("SomeTest callme called")

    def test_unit1(self):
        print("test_unit1 method called")

如果您在没有输出捕获的情况下运行此命令

$ pytest -q -s test_module.py
callattr_ahead_of_alltests called
callme called!
callme other called
SomeTest callme called
test_method1 called
.test_method2 called
.test other
.test_unit1 method called
.
4 passed in 0.12s