diff --git a/tornado/options.py b/tornado/options.py
index ba16b1a7..bdb5baa0 100644
--- a/tornado/options.py
+++ b/tornado/options.py
@@ -132,8 +132,10 @@ class OptionParser(object):
         return name in self._options
 
     def __getitem__(self, name):
-        name = self._normalize_name(name)
-        return self._options[name].value()
+        return self.__getattr__(name)
+
+    def __setitem__(self, name, value):
+        return self.__setattr__(name, value)
 
     def items(self):
         """A sequence of (name, value) pairs.

Options should support setitem
From http://stackoverflow.com/questions/33411269/attributeerror-in-python-tornado-to-configure-log-into-a-file/33417289

Options currently override getattr, setattr, and getitem. Item and attribute syntax should be symmetric so we need a setitem override to match setattr.
diff --git a/tornado/test/options_test.py b/tornado/test/options_test.py
index c32184bb..2f2384b2 100644
--- a/tornado/test/options_test.py
+++ b/tornado/test/options_test.py
@@ -131,6 +131,12 @@ class OptionsTest(unittest.TestCase):
         options = self._sample_options()
         self.assertEqual(1, options['a'])
 
+    def test_setitem(self):
+        options = OptionParser()
+        options.define('foo', default=1, type=int)
+        options['foo'] = 2
+        self.assertEqual(options['foo'], 2)
+
     def test_items(self):
         options = self._sample_options()
         # OptionParsers always define 'help'.

pip install -e .
parse_log_pytest
pytest
futures mock monotonic trollius pytest
apt-get update apt-get install -y gcc
3.5
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///opt/conda/conda-bld/attrs_1642510447205/work
certifi==2021.5.30
futures==2.2.0
importlib-metadata @ file:///tmp/build/80754af9/importlib-metadata_1631916693255/work
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
mock==5.2.0
monotonic==1.6
more-itertools @ file:///tmp/build/80754af9/more-itertools_1637733554872/work
packaging @ file:///tmp/build/80754af9/packaging_1637314298585/work
pluggy @ file:///tmp/build/80754af9/pluggy_1615976315926/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pyparsing @ file:///tmp/build/80754af9/pyparsing_1635766073266/work
pytest==6.2.4
six==1.17.0
toml @ file:///tmp/build/80754af9/toml_1616166611790/work
-e git+https://github.com/tornadoweb/tornado.git@1ecc7386da17df3f1dfd100845355f7211119a62#egg=tornado
trollius==2.1.post2
typing_extensions @ file:///opt/conda/conda-bld/typing_extensions_1647553014482/work
zipp @ file:///tmp/build/80754af9/zipp_1633618647012/work

name: tornado
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=21.4.0=pyhd3eb1b0_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - importlib-metadata=4.8.1=py36h06a4308_0
  - importlib_metadata=4.8.1=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - more-itertools=8.12.0=pyhd3eb1b0_0
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - packaging=21.3=pyhd3eb1b0_0
  - pip=21.2.2=py36h06a4308_0
  - pluggy=0.13.1=py36h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pyparsing=3.0.4=pyhd3eb1b0_0
  - pytest=6.2.4=py36h06a4308_2
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - toml=0.10.2=pyhd3eb1b0_0
  - typing_extensions=4.1.1=pyh06a4308_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.6.0=pyhd3eb1b0_0
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - futures==2.2.0
      - mock==5.2.0
      - monotonic==1.6
      - six==1.17.0
      - trollius==2.1.post2
prefix: /opt/conda/envs/tornado

tornado/test/options_test.py::OptionsTest::test_setitem
tornado/test/options_test.py::OptionsTest::test_as_dict tornado/test/options_test.py::OptionsTest::test_dash_underscore_cli tornado/test/options_test.py::OptionsTest::test_dash_underscore_file tornado/test/options_test.py::OptionsTest::test_dash_underscore_introspection tornado/test/options_test.py::OptionsTest::test_error_redefine tornado/test/options_test.py::OptionsTest::test_getitem tornado/test/options_test.py::OptionsTest::test_group_dict tornado/test/options_test.py::OptionsTest::test_help tornado/test/options_test.py::OptionsTest::test_items tornado/test/options_test.py::OptionsTest::test_iter tornado/test/options_test.py::OptionsTest::test_mock_patch tornado/test/options_test.py::OptionsTest::test_multiple_int tornado/test/options_test.py::OptionsTest::test_multiple_string tornado/test/options_test.py::OptionsTest::test_parse_callbacks tornado/test/options_test.py::OptionsTest::test_parse_command_line tornado/test/options_test.py::OptionsTest::test_parse_config_file tornado/test/options_test.py::OptionsTest::test_setattr tornado/test/options_test.py::OptionsTest::test_setattr_type_check tornado/test/options_test.py::OptionsTest::test_setattr_with_callback tornado/test/options_test.py::OptionsTest::test_subcommand tornado/test/options_test.py::OptionsTest::test_types
tornado/options.py
tornado/options.py