cpython/Lib/test/test_capi.py

# Run the _testcapi module tests (tests for the Python/C API):  by defn,
# these are all functions _testcapi exports whose name begins with 'test_'.

import sys
from test import test_support
import _testcapi

for name in dir(_testcapi):
    if name.startswith('test_'):
        test = getattr(_testcapi, name)
        if test_support.verbose:
            print "internal", name
        try:
            test()
        except _testcapi.error:
            raise test_support.TestFailed, sys.exc_info()[1]

# some extra thread-state tests driven via _testcapi
def TestThreadState():
    import thread
    import time

    if test_support.verbose:
        print "auto-thread-state"

    idents = []

    def callback():
        idents.append(thread.get_ident())

    _testcapi._test_thread_state(callback)
    time.sleep(1)
    # Check our main thread is in the list exactly 3 times.
    if idents.count(thread.get_ident()) != 3:
        raise test_support.TestFailed, \
              "Couldn't find main thread correctly in the list"

try:
    _testcapi._test_thread_state
    have_thread_state = True
except AttributeError:
    have_thread_state = False

if have_thread_state:
    TestThreadState()
    import threading
    t=threading.Thread(target=TestThreadState)
    t.start()