conftest.py 可以从 pytest.ini 读取现有值吗？

Question

conftest.py can be used to define properties in pytest.ini with parser.addini() but can conftest.py also read existing values from pytest.ini?

I would like to look at the value of a parameter in pytest.ini and use it to set the default value of another parameter in pytest.ini

Is this possible without having to use configparser myself in conftest.py?

Answer 1

I would like to look at the value of a parameter in pytest.ini and use it to set the default value of another parameter in pytest.ini

Best is to add a custom impl of the pytest_configure hook. Example: assume you have two custom ini options defined in your conftest.py :

def pytest_addoption(parser):
    parser.addini("fizz", help="help for my key", default="buzz")
    parser.addini("spam", help="help for my key", default="eggs")

Now spam should be set to bacon whenever fizz is not buzz (not the default value). Extend conftest.py with:

def pytest_configure(config):
    fizz = config.getini("fizz")
    spam = config.getini("spam")
    print("values parsed from ini: fizz:", fizz, "spam:", spam)

    if not fizz == "buzz":
        # override parsed ini value
        config._inicache["spam"] = "bacon"

    print("spam was replaced to:", config.getini("spam"))

When running pytest -s (and fizz set to something else than buzz in pytest.ini ), you will get the following output:

values parsed from ini: fizz: fuzz spam: eggs
spam was replaced to: bacon
============================= test session starts =============================
...