Avoid using try_import

testtools/testcase.py

@@ -26,7 +26,6 @@
 
 from testtools import content
 from testtools.compat import reraise
-from testtools.helpers import try_import
 from testtools.matchers import (
     Annotate,
     Contains,
@@ -166,7 +165,10 @@ def gather_details(source_dict, target_dict):
 # Circular import: fixtures imports gather_details from here, we import
 # fixtures, leading to gather_details not being available and fixtures being
 # unable to import it.
-fixtures = try_import("fixtures")
+try:
+    import fixtures
+except ImportError:
+    fixtures = None
 
 
 class UseFixtureProtocol(Protocol):

testtools/tests/test_fixturesupport.py

@@ -8,7 +8,6 @@
     content_type,
 )
 from testtools.compat import _b
-from testtools.helpers import try_import
 from testtools.matchers import (
     Contains,
     Equals,
@@ -17,8 +16,15 @@
     ExtendedTestResult,
 )
 
-fixtures = try_import("fixtures")
-LoggingFixture = try_import("fixtures.tests.helpers.LoggingFixture")
+try:
+    import fixtures
+except ImportError:
+    fixtures = None
+
+try:
+    from fixtures.tests.helpers import LoggingFixture
+except ImportError:
+    LoggingFixture = None
 
 
 class TestFixtureSupport(TestCase):

testtools/tests/test_run.py

@@ -12,15 +12,21 @@
 import testtools
 from testtools import TestCase, run, skipUnless
 from testtools.compat import _b
-from testtools.helpers import try_import
 from testtools.matchers import (
     Contains,
     DocTestMatches,
     MatchesRegex,
 )
 
-fixtures = try_import("fixtures")
-testresources = try_import("testresources")
+try:
+    import fixtures
+except ImportError:
+    fixtures = None
+
+try:
+    import testresources
+except ImportError:
+    testresources = None
 
 
 if fixtures:

testtools/tests/test_testresult.py

@@ -54,7 +54,6 @@
     text_content,
 )
 from testtools.content_type import UTF8_TEXT, ContentType
-from testtools.helpers import try_import
 from testtools.matchers import (
     AllMatch,
     Contains,
@@ -86,7 +85,10 @@
     run_with_stack_hidden,
 )
 
-testresources = try_import("testresources")
+try:
+    import testresources
+except ImportError:
+    testresources = None
 
 
 def _utcfromtimestamp(t):

testtools/tests/test_testsuite.py

@@ -14,13 +14,15 @@
     TestCase,
     iterate_tests,
 )
-from testtools.helpers import try_import
 from testtools.matchers import DocTestMatches, Equals
 from testtools.testresult.doubles import StreamResult as LoggingStream
 from testtools.tests.helpers import LoggingResult
 from testtools.testsuite import FixtureSuite, sorted_tests
 
-FunctionFixture = try_import("fixtures.FunctionFixture")
+try:
+    from fixtures import FunctionFixture
+except ImportError:
+    FunctionFixture = None
 
 
 class Sample(TestCase):

testtools/tests/twistedsupport/_helpers.py

@@ -5,9 +5,11 @@
 ]
 
 from testtools import TestCase
-from testtools.helpers import try_import
 
-defer = try_import("twisted.internet.defer")
+try:
+    from twisted.internet import defer
+except ImportError:
+    defer = None
 
 
 class NeedsTwistedTestCase(TestCase):

testtools/tests/twistedsupport/test_deferred.py

@@ -2,7 +2,6 @@
 
 """Tests for testtools._deferred."""
 
-from testtools.helpers import try_import
 from testtools.matchers import (
     Equals,
     MatchesException,
@@ -11,11 +10,21 @@
 
 from ._helpers import NeedsTwistedTestCase
 
-DeferredNotFired = try_import("testtools.twistedsupport._deferred.DeferredNotFired")
-extract_result = try_import("testtools.twistedsupport._deferred.extract_result")
+try:
+    from testtools.twistedsupport._deferred import DeferredNotFired, extract_result
+except ImportError:
+    DeferredNotFired = None
+    extract_result = None
 
-defer = try_import("twisted.internet.defer")
-Failure = try_import("twisted.python.failure.Failure")
+try:
+    from twisted.internet import defer
+except ImportError:
+    defer = None
+
+try:
+    from twisted.python.failure import Failure
+except ImportError:
+    Failure = None
 
 
 class TestExtractResult(NeedsTwistedTestCase):

testtools/tests/twistedsupport/test_runtest.py

@@ -11,7 +11,6 @@
     TestResult,
     skipIf,
 )
-from testtools.helpers import try_import
 from testtools.matchers import (
     AfterPreprocessing,
     Contains,
@@ -33,24 +32,44 @@
 
 from ._helpers import NeedsTwistedTestCase
 
-DebugTwisted = try_import("testtools.twistedsupport._deferreddebug.DebugTwisted")
-
-assert_fails_with = try_import("testtools.twistedsupport.assert_fails_with")
-AsynchronousDeferredRunTest = try_import(
-    "testtools.twistedsupport.AsynchronousDeferredRunTest"
-)
-flush_logged_errors = try_import("testtools.twistedsupport.flush_logged_errors")
-SynchronousDeferredRunTest = try_import(
-    "testtools.twistedsupport.SynchronousDeferredRunTest"
-)
-
-defer = try_import("twisted.internet.defer")
-failure = try_import("twisted.python.failure")
-log = try_import("twisted.python.log")
-DelayedCall = try_import("twisted.internet.base.DelayedCall")
-_get_global_publisher_and_observers = try_import(
-    "testtools.twistedsupport._runtest._get_global_publisher_and_observers"
-)
+try:
+    from testtools.twistedsupport._deferreddebug import DebugTwisted
+except ImportError:
+    DebugTwisted = None
+
+try:
+    from testtools.twistedsupport import (
+        AsynchronousDeferredRunTest,
+        SynchronousDeferredRunTest,
+        assert_fails_with,
+        flush_logged_errors,
+    )
+except ImportError:
+    assert_fails_with = None
+    AsynchronousDeferredRunTest = None
+    flush_logged_errors = None
+    SynchronousDeferredRunTest = None
+
+try:
+    from twisted.internet import defer
+except ImportError:
+    defer = None
+
+try:
+    from twisted.python import failure, log
+except ImportError:
+    failure = None
+    log = None
+
+try:
+    from twisted.internet.base import DelayedCall
+except ImportError:
+    DelayedCall = None
+
+try:
+    from testtools.twistedsupport._runtest import _get_global_publisher_and_observers
+except ImportError:
+    _get_global_publisher_and_observers = None
 
 
 class X:

testtools/tests/twistedsupport/test_spinner.py

@@ -6,7 +6,6 @@
 import signal
 
 from testtools import skipIf
-from testtools.helpers import try_import
 from testtools.matchers import (
     Equals,
     Is,
@@ -16,10 +15,20 @@
 
 from ._helpers import NeedsTwistedTestCase
 
-_spinner = try_import("testtools.twistedsupport._spinner")
+try:
+    from testtools.twistedsupport import _spinner
+except ImportError:
+    _spinner = None
 
-defer = try_import("twisted.internet.defer")
-Failure = try_import("twisted.python.failure.Failure")
+try:
+    from twisted.internet import defer
+except ImportError:
+    defer = None
+
+try:
+    from twisted.python.failure import Failure
+except ImportError:
+    Failure = None
 
 
 class TestNotReentrant(NeedsTwistedTestCase):