import sys

import pytest

PY2 = sys.version_info[0] < 3
PY3 = sys.version_info[0] >= 3

class DummyCollector(pytest.collect.File):
    def collect(self):
         return []

def pytest_pycollect_makemodule(path, parent):
    if "py3" in path.basename and not PY3:
        return DummyCollector(path, parent=parent)
    if "py2" in path.basename and not PY2:
        return DummyCollector(path, parent=parent)