[Python-Dev] regrtest.py mystery (original) (raw)

Tim Peters tim.one@home.com
Sat, 15 Dec 2001 16:20:32 -0500

We do this after running every test:

    # Unload the newly imported modules (best effort finalization)
    for module in sys.modules.keys():
        if module not in save_modules and module.startswith("test."):
            test_support.unload(module)

Unfortunately, that doesn't nuke whatever damaged non-test module objects may have been left behind. If I change it to make a truly best effort:

        if module not in save_modules:
            test_support.unload(module)

then about a dozen std tests fail in mysterious ways, but only when running more than one test. Like just running

test_email test_string

causes test_string to die like so:

python ../lib/test/regrtest.py -v test_email test_string

...

test test_string crashed -- exceptions.AttributeError: 'NoneType' object has no attribute 'get' Traceback (most recent call last): File "../lib/test/regrtest.py", line 305, in runtest the_module = import(test, globals(), locals(), []) File "../lib/test\test_string.py", line 34, in ? string_tests.run_method_tests(test) File "../lib/test\string_tests.py", line 233, in run_method_tests verify('hello world'.encode('zlib') == data) File "C:\CODE\PYTHON\lib\encodings_init_.py", line 43, in search_function entry = _cache.get(encoding,_unknown) AttributeError: 'NoneType' object has no attribute 'get'

It seems generally the case that these failures are due to various module-level names getting rebound to None. A simpler example:

python ../lib/test/regrtest.py -v test_string test_string

...

test test_string crashed -- exceptions.AttributeError: 'NoneType' object has no attribute 'compress' Traceback (most recent call last): File "../lib/test/regrtest.py", line 305, in runtest the_module = import(test, globals(), locals(), []) File "../lib/test\test_string.py", line 34, in ? string_tests.run_method_tests(test) File "../lib/test\string_tests.py", line 233, in run_method_tests verify('hello world'.encode('zlib') == data) File "C:\CODE\PYTHON\lib\encodings\zlib_codec.py", line 25, in zlib_encode output = zlib.compress(input) AttributeError: 'NoneType' object has no attribute 'compress'

What's up with that? So far, they all seem to involve the encodings directory ...