Python 将数字对与包含数字对的字典匹配

这里有一个 Select ，用一个测试来证明它通过了您的所有示例:

import pytest

instance_sizes = [
    {"name": "t3a.nano", "cpu": 2, "mem": 0.5},
    {"name": "t3a.micro", "cpu": 2, "mem": 1},
    {"name": "t3a.small", "cpu": 2, "mem": 2},
    {"name": "t3a.medium/c5a.large", "cpu": 2, "mem": 4},
    {"name": "t3a/m5a.large", "cpu": 2, "mem": 8},
    {"name": "c5a.xlarge", "cpu": 4, "mem": 8},
    {"name": "t3a/m5a.xlarge", "cpu": 4, "mem": 16},
    {"name": "c5a.2xlarge", "cpu": 8, "mem": 16},
    {"name": "t3a/m5a.2xlarge", "cpu": 8, "mem": 32},
]


def get_instance_size(cpu, mem):
    return next(
        x
        for x in sorted(instance_sizes, key=lambda size: size["cpu"])
        if x["cpu"] >= cpu and x["mem"] >= mem
    )


@pytest.mark.parametrize(
    "cpu,mem,expected",
    (
        (1.8, 6, "t3a/m5a.large"),
        (0.1, 6, "t3a/m5a.large"),
        (2.1, 6, "c5a.xlarge"),
        (6, 16, "c5a.2xlarge"),
    ),
)
def test_get_instance_size(cpu, mem, expected):
    res = get_instance_size(cpu, mem)

    assert res is not None
    assert res["name"] == expected

对上面的代码运行pytest会导致:

============================= test session starts ==============================
platform linux -- Python 3.11.3, pytest-7.3.0, pluggy-1.0.0 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /home/lars/tmp/python
collecting ... collected 4 items

flavors.py::test_get_instance_size[1.8-6-t3a/m5a.large] PASSED           [ 25%]
flavors.py::test_get_instance_size[0.1-6-t3a/m5a.large] PASSED           [ 50%]
flavors.py::test_get_instance_size[2.1-6-c5a.xlarge] PASSED              [ 75%]
flavors.py::test_get_instance_size[6-16-c5a.2xlarge] PASSED              [100%]

============================== 4 passed in 0.01s ===============================

在上面的代码中，如果找不到匹配项，get_instance_size将引发StopIteration异常.