Can I explicitly specify multiple tests in PyTest?

Question

I know I can specify a single test to run in PyTest with the following command:

py.test test.py::my_test_class::my_test_function.

Is there a way to explicitly specify multiple tests to run, without running ALL the tests?

I could run the py.test command in a for loop specifying a different test each time, but is there a better solution?

Answer 1

You can put your tests in a file, implement the modifier hook to filter the tests to execute based on whether or not they are present in the file. Here's an example:

Test file# 1

$ cat test_foo.py 
def test_001():
    pass
def test_002():
    pass
$ 

Test file# 2

$ cat test_bar.py 
def test_001():
    pass
def test_003():
    pass
$ 

Source file containing tests to execute

$ cat my_tests 
test_001
test_002
$ 

Modifier hook

$ cat conftest.py 
import pytest

def pytest_addoption(parser):
    parser.addoption("--testsource", action="store", default=None,
                     help="File containing tests to run")

def pytest_collection_modifyitems(session, config, items):
    testsource = config.getoption("--testsource")
    if not testsource:
        return

    my_tests = []
    with open(testsource) as ts:
        my_tests = list(map(lambda x: x.strip(),ts.readlines()))

    selected = []
    deselected = []
    for item in items:
        deselected.append(item) if item.name not in my_tests else selected.append(item)

    if deselected:
        config.hook.pytest_deselected(items=deselected)
        items[:] = selected
    print('Deselected: {}'.format(deselected))
    print('Selected: {}'.format(items))
$ 

Execution output

$ py.test -vs --testsource my_tests
Test session starts (platform: linux, Python 3.5.1, pytest 2.8.7, pytest-sugar 0.5.1)
cachedir: .cache
rootdir: /home/sharad/tmp, inifile: 
plugins: cov-2.2.1, timeout-1.0.0, sugar-0.5.1, json-0.4.0, html-1.8.0, spec-1.0.1
Deselected: [<Function 'test_003'>]
Selected: [<Function 'test_001'>, <Function 'test_001'>, <Function 'test_002'>]

 test_bar.pytest_001 ✓                                                                                                                                                                                33% ███��      
 test_foo.pytest_001 ✓                                                                                                                                                                                67% ██████▋   
 test_foo.pytest_002 ✓                                                                                                                                                                               100% ██████████

Results (0.05s):
       3 passed
       1 deselected
$