No more raising of string exceptions!
The next step of PEP 352 (for 2.6) causes raising a string exception to trigger
a TypeError. Trying to catch a string exception raises a DeprecationWarning.
References to string exceptions has been removed from the docs since they are
now just an error.
diff --git a/Lib/test/test_pep352.py b/Lib/test/test_pep352.py
index b2322b0..4ce25d6 100644
--- a/Lib/test/test_pep352.py
+++ b/Lib/test/test_pep352.py
@@ -2,7 +2,7 @@
import __builtin__
import exceptions
import warnings
-from test.test_support import run_unittest
+from test.test_support import run_unittest, guard_warnings_filter
import os
from platform import system as platform_system
@@ -113,13 +113,8 @@
"""Test usage of exceptions"""
- def setUp(self):
- self._filters = warnings.filters[:]
-
- def tearDown(self):
- warnings.filters = self._filters[:]
-
def test_raise_classic(self):
+ # Raising a classic class is okay (for now).
class ClassicClass:
pass
try:
@@ -136,6 +131,10 @@
self.fail("unable to raise class class instance")
def test_raise_new_style_non_exception(self):
+ # You cannot raise a new-style class that does not inherit from
+ # BaseException; the ability was not possible until BaseException's
+ # introduction so no need to support new-style objects that do not
+ # inherit from it.
class NewStyleClass(object):
pass
try:
@@ -143,35 +142,52 @@
except TypeError:
pass
except:
- self.fail("unable to raise new-style class")
+ self.fail("able to raise new-style class")
try:
raise NewStyleClass()
except TypeError:
pass
except:
- self.fail("unable to raise new-style class instance")
+ self.fail("able to raise new-style class instance")
def test_raise_string(self):
- warnings.resetwarnings()
- warnings.filterwarnings("error")
+ # Raising a string raises TypeError.
try:
raise "spam"
- except DeprecationWarning:
+ except TypeError:
pass
except:
- self.fail("raising a string did not cause a DeprecationWarning")
+ self.fail("was able to raise a string exception")
def test_catch_string(self):
- # Test will be pertinent when catching exceptions raises a
- # DeprecationWarning
- warnings.filterwarnings("ignore", "raising")
- str_exc = "spam"
- try:
- raise str_exc
- except str_exc:
- pass
- except:
- self.fail("catching a string exception failed")
+ # Catching a string should trigger a DeprecationWarning.
+ with guard_warnings_filter():
+ warnings.resetwarnings()
+ warnings.filterwarnings("error")
+ str_exc = "spam"
+ try:
+ try:
+ raise StandardError
+ except str_exc:
+ pass
+ except DeprecationWarning:
+ pass
+ except StandardError:
+ self.fail("catching a string exception did not raise "
+ "DeprecationWarning")
+ # Make sure that even if the string exception is listed in a tuple
+ # that a warning is raised.
+ try:
+ try:
+ raise StandardError
+ except (AssertionError, str_exc):
+ pass
+ except DeprecationWarning:
+ pass
+ except StandardError:
+ self.fail("catching a string exception specified in a tuple did "
+ "not raise DeprecationWarning")
+
def test_main():
run_unittest(ExceptionClassTests, UsageTests)