ERF: use py.test 2 ini-file configuration.

we can now check for py.test version, and get finally rid of the
redundant conftest.py files. we now have only one conftest.py file
for bimdp and mdp.

conftest.py

@@ -1,13 +1,64 @@
-collect_ignore = ['build', 'cover', 'html',
-                  ]
+# global hooks for py.test
+import tempfile
+import os
+import shutil
+import glob
+import mdp
+import py.test
 
-def _have_option(parser, optionname):
-    return any(optionname == option.get_opt_string()
-               for option in parser._anonymous.options)
+_err_str = """
+IMPORTANT: some tests use random numbers. This could
+occasionally lead to failures due to numerical degeneracies.
+To rule this out, please run the tests more than once.
+If you get reproducible failures please report a bug!
+"""
+
+def pytest_configure(config):
+    seed = config.getvalue("seed")
+    # if seed was not set by the user, we set one now
+    if seed is None or seed == ('NO', 'DEFAULT'):
+        config.option.seed = int(mdp.numx_rand.randint(2**31-1))
+
+def pytest_unconfigure(config):
+    # remove garbage created during tests
+    # note that usage of TemporaryDirectory is not enough to assure
+    # that all garbage is removed, expacially because we use subprocesses
+    shutil.rmtree(py.test.mdp_tempdirname, ignore_errors=True)
+    # if pp was monkey-patched, remove any stale pp4mdp directories
+    if mdp.config.pp_monkeypatch_dirname:
+        monkey_dirs = os.path.join(mdp.config.pp_monkeypatch_dirname,
+                                   mdp.parallel.pp_support.TEMPDIR_PREFIX) 
+        [shutil.rmtree(d, ignore_errors=True) for d in glob.glob(monkey_dirs+'*')]
+
+def pytest_runtest_setup(item):
+    # set random seed before running each test
+    # so that a failure in a test can be reproduced just running
+    # that particular test. if this was not done, you would need
+    # to run the whole test suite again
+    mdp.numx_rand.seed(item.config.option.seed)
 
 def pytest_addoption(parser):
-    """Add random seed option to py.test
+    """Add random seed option to py.test.
     """
-    if not _have_option(parser, '--seed'):
-        parser.addoption('--seed', dest='seed', type=int, action='store',
-                         help='set random seed')
+    parser.addoption('--seed', dest='seed', type=int, action='store',
+                     help='set random seed')
+
+def pytest_report_header(config):
+    # report the random seed before and after running the tests
+    return '%s\nRandom Seed: %d\n' % (mdp.config.info(), config.option.seed)
+
+def pytest_terminal_summary(terminalreporter):
+    # add a note about error due to randomness only if an error or a failure
+    # occured
+    t = terminalreporter
+    t.write_sep("=", "NOTE")
+    t.write_line("%s\nRandom Seed: %d" % (mdp.config.info(),
+                                          t.config.option.seed))
+    if 'failed' in t.stats or 'error' in t.stats:
+        t.write_line(_err_str)
+
+def pytest_namespace():
+    # get temporary directory to put temporary files
+    # will be deleted at the end of the test run
+    dirname = tempfile.mkdtemp(suffix='.tmp', prefix='MDPtestdir_')
+    return dict(mdp_tempdirname=dirname)

pytest.ini

@@ -0,0 +1,3 @@
+[pytest]
+norecursedirs = build .git cover html dist
+minversion = 2.1.2