cpython/Lib/importlib/test/extension/test_path_hook.py

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from importlib import _bootstrap
from . import util
import collections
import imp
import sys
import unittest
class PathHookTests(unittest.TestCase):
"""Test the path hook for extension modules."""
# XXX Should it only succeed for pre-existing directories?
# XXX Should it only work for directories containing an extension module?
def hook(self, entry):
Make importlib.abc.SourceLoader the primary mechanism for importlib. This required moving the class from importlib/abc.py into importlib/_bootstrap.py and jiggering some code to work better with the class. This included changing how the file finder worked to better meet import semantics. This also led to fixing importlib to handle the empty string from sys.path as import currently does (and making me wish we didn't support that instead just required people to insert '.' instead to represent cwd). It also required making the new set_data abstractmethod create any needed subdirectories implicitly thanks to __pycache__ (it was either this or grow the SourceLoader ABC to gain an 'exists' method and either a mkdir method or have set_data with no data arg mean to create a directory). Lastly, as an optimization the file loaders cache the file path where the finder found something to use for loading (this is thanks to having a sourceless loader separate from the source loader to simplify the code and cut out stat calls). Unfortunately test_runpy assumed a loader would always work for a module, even if you changed from underneath it what it was expected to work with. By simply dropping the previous loader in test_runpy so the proper loader can be returned by the finder fixed the failure. At this point importlib deviates from import on two points: 1. The exception raised when trying to import a file is different (import does an explicit file check to print a special message, importlib just says the path cannot be imported as if it was just some module name). 2. the co_filename on a code object is not being set to where bytecode was actually loaded from instead of where the marshalled code object originally came from (a solution for this has already been agreed upon on python-dev but has not been implemented yet; issue8611).
2010-07-03 18:48:25 -03:00
return _bootstrap._file_path_hook(entry)
def test_success(self):
# Path hook should handle a directory where a known extension module
# exists.
self.assertTrue(hasattr(self.hook(util.PATH), 'find_module'))
def test_main():
from test.support import run_unittest
run_unittest(PathHookTests)
if __name__ == '__main__':
test_main()