Suggest narrowing for None in union attribute errors

[dhruvildarji]

Summary

When accessing an attribute on a union type that includes None, mypy now emits a note suggesting the user narrow the type with an if x is not None guard:

error: Item "None" of "str | None" has no attribute "startswith"
note: You can use "if s is not None" to guard against a None value

This is especially helpful for beginners who may not know about type narrowing. The note is only shown when:

• The offending union item is None (not for arbitrary Union[A, B])
• The variable name can be extracted from the AST context (simple names like x, or member access like self.a)
• For complex expressions like items[0].attr, the note is skipped to avoid unhelpful suggestions

Fixes #17036

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

prefect (https://github.com/PrefectHQ/prefect)
+ src/prefect/_internal/analytics/client.py:120: note: You can use "if _amplitude_client is not None" to guard against a None value
+ src/prefect/_internal/schemas/validators.py:237: note: You can use "if anchor_date.tzinfo is not None" to guard against a None value
+ src/prefect/_internal/compatibility/deprecated.py:106: note: You can use "if end_date is not None" to guard against a None value
+ src/prefect/futures.py:327: note: You can use "if task_run.state is not None" to guard against a None value
+ src/prefect/task_runners.py:724: note: You can use "if self._executor is not None" to guard against a None value
+ src/prefect/deployments/runner.py:875: note: You can use "if value is not None" to guard against a None value
+ src/prefect/server/services/task_run_recorder.py:67: note: You can use "if task_run.state is not None" to guard against a None value
+ src/prefect/flow_engine.py:513: note: You can use "if self.flow_run is not None" to guard against a None value
+ src/prefect/flow_engine.py:1117: note: You can use "if self.flow_run is not None" to guard against a None value
+ src/prefect/server/orchestration/global_policy.py:462: note: You can use "if context.proposed_state is not None" to guard against a None value
+ src/prefect/server/orchestration/global_policy.py:466: note: You can use "if context.proposed_state is not None" to guard against a None value
+ src/prefect/server/orchestration/global_policy.py:467: note: You can use "if context.proposed_state is not None" to guard against a None value
+ src/prefect/task_engine.py:944: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/task_engine.py:946: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/task_engine.py:1138: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/task_engine.py:1144: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/task_engine.py:1144: note: You can use "if flow_run is not None" to guard against a None value
+ src/prefect/task_engine.py:1572: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/task_engine.py:1574: note: You can use "if self.task_run is not None" to guard against a None value
+ src/prefect/server/api/deployments.py:86: note: You can use "if updated_by is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:140: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:160: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:175: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:190: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:205: note: You can use "if flow_run_ctx.flow is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:220: note: You can use "if flow_run_ctx.flow is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:235: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:258: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/flow_run.py:335: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/runtime/deployment.py:171: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/flow_runs.py:260: note: You can use "if context.flow_run is not None" to guard against a None value
+ src/prefect/flow_runs.py:296: note: You can use "if context.flow_run is not None" to guard against a None value
+ src/prefect/flow_runs.py:414: note: You can use "if context.flow_run is not None" to guard against a None value
+ src/prefect/flow_runs.py:450: note: You can use "if context.flow_run is not None" to guard against a None value
+ src/prefect/flow_runs.py:461: note: You can use "if context.flow_run is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:185: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:187: note: You can use "if task_run_ctx is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:192: note: You can use "if task_run_ctx is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:382: note: You can use "if flow_run_ctx.flow_run is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:384: note: You can use "if task_run_ctx is not None" to guard against a None value
+ src/prefect/deployments/flow_runs.py:389: note: You can use "if task_run_ctx is not None" to guard against a None value
+ src/prefect/deployments/base.py:71: note: You can use "if contents is not None" to guard against a None value
+ src/prefect/deployments/base.py:83: note: You can use "if contents is not None" to guard against a None value
+ src/prefect/deployments/base.py:95: note: You can use "if contents is not None" to guard against a None value
+ src/prefect/deployments/base.py:108: note: You can use "if contents is not None" to guard against a None value
+ src/prefect/cli/flow_run.py:289: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/flow_run.py:290: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/flow_run.py:291: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/flow_run.py:297: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/cloud/__init__.py:371: note: You can use "if workspace is not None" to guard against a None value
+ src/prefect/cli/cloud/__init__.py:373: note: You can use "if workspace is not None" to guard against a None value
+ src/prefect/infrastructure/provisioners/container_instance.py:732: note: You can use "if credentials_block_schema is not None" to guard against a None value
+ src/prefect/infrastructure/provisioners/cloud_run.py:239: note: You can use "if credentials_block_schema is not None" to guard against a None value
+ src/prefect/cli/_server_utils.py:219: note: You can use "if settings.server.database.connection_url is not None" to guard against a None value
+ src/prefect/cli/work_pool.py:258: note: You can use "if work_pool.status is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/work_pool.py:264: note: You can use "if work_pool.status is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/flow_run.py:264: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/flow_run.py:265: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/flow_run.py:266: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/flow_run.py:272: note: You can use "if flow_run.state is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/cloud.py:442: note: You can use "if workspace is not None" to guard against a None value
+ src/prefect/cli/_cyclopts/cloud.py:444: note: You can use "if workspace is not None" to guard against a None value

colour (https://github.com/colour-science/colour)
+ colour/utilities/network.py:1459: note: You can use "if port_source is not None" to guard against a None value
+ colour/utilities/network.py:1507: note: You can use "if port_source is not None" to guard against a None value
+ colour/io/tabular.py:164: note: You can use "if data.dtype is not None" to guard against a None value

Tanjun (https://github.com/FasterSpeeding/Tanjun)
+ tanjun/dependencies/limiters.py:814: note: You can use "if resource is not None" to guard against a None value

schemathesis (https://github.com/schemathesis/schemathesis)
+ src/schemathesis/generation/hypothesis/builder.py:154: note: You can use "if default is not None" to guard against a None value

operator (https://github.com/canonical/operator)
+ ops/lib/__init__.py:272: note: You can use "if self.spec.loader is not None" to guard against a None value

cki-lib (https://gitlab.com/cki-project/cki-lib)
+ cki_lib/kcidb/checks.py:81: note: You can use "if dw_all is not None" to guard against a None value
+ tests/test_gitlab.py:251: note: You can use "if gl_setup'.gl_group is not None" to guard against a None value
+ tests/test_gitlab.py:256: note: You can use "if gl_setup''.gl_project is not None" to guard against a None value
+ tests/test_gitlab.py:261: note: You can use "if gl_setup'''.gl_project is not None" to guard against a None value
+ tests/test_cronjob.py:83: note: You can use "if runner is not None" to guard against a None value
+ tests/test_cronjob.py:109: note: You can use "if runner is not None" to guard against a None value
+ tests/test_cronjob.py:117: note: You can use "if runner is not None" to guard against a None value
+ tests/test_cronjob.py:127: note: You can use "if runner is not None" to guard against a None value

core (https://github.com/home-assistant/core)
+ homeassistant/components/minecraft_server/api.py:95: note: You can use "if self._server is not None" to guard against a None value

pytest (https://github.com/pytest-dev/pytest)
+ testing/test_collection.py:87: note: You can use "if modcol is not None" to guard against a None value
+ testing/test_collection.py:88: note: You can use "if modcol is not None" to guard against a None value
+ testing/test_collection.py:89: note: You can use "if modcol is not None" to guard against a None value
+ testing/_py/test_local.py:851: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:854: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:905: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:907: note: You can use "if y is not None" to guard against a None value
+ testing/_py/test_local.py:916: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:917: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:922: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:933: note: You can use "if x is not None" to guard against a None value
+ testing/_py/test_local.py:1274: note: You can use "if cmd is not None" to guard against a None value
+ testing/_py/test_local.py:1276: note: You can use "if cmd is not None" to guard against a None value
+ testing/_py/test_local.py:1277: note: You can use "if x is not None" to guard against a None value

mitmproxy (https://github.com/mitmproxy/mitmproxy)
+ web/gen/web_columns.py:22: note: You can use "if match is not None" to guard against a None value
+ web/gen/tflow_js.py:31: note: You can use "if tf_http.response is not None" to guard against a None value

steam.py (https://github.com/Gobot1234/steam.py)
+ steam/id.py:558: note: You can use "if session is not None" to guard against a None value

discord.py (https://github.com/Rapptz/discord.py)
+ discord/appinfo.py:464: note: You can use "if guild_install_permissions is not None" to guard against a None value
+ discord/appinfo.py:484: note: You can use "if user_install_permissions is not None" to guard against a None value
+ discord/guild.py:3413: note: You can use "if channel is not None" to guard against a None value

ibis (https://github.com/ibis-project/ibis)
+ ibis/backends/sql/datatypes.py:1371: note: You can use "if scale is not None" to guard against a None value
+ ibis/expr/types/generic.py:1464: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/generic.py:1478: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/generic.py:1664: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/generic.py:1689: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/relations.py:595: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/relations.py:610: note: You can use "if data_mapper is not None" to guard against a None value
+ ibis/expr/types/relations.py:1474: note: You can use "if metrics is not None" to guard against a None value
+ ibis/expr/types/relations.py:1475: note: You can use "if metrics is not None" to guard against a None value
+ ibis/expr/types/relations.py:4527: note: You can use "if match_result is not None" to guard against a None value
+ ibis/backends/databricks/__init__.py:217: note: You can use "if schema is not None" to guard against a None value
+ ibis/backends/oracle/tests/conftest.py:146: note: You can use "if schema is not None" to guard against a None value
+ ibis/backends/druid/tests/conftest.py:86: note: You can use "if match is not None" to guard against a None value
+ ibis/backends/sqlite/__init__.py:522: note: You can use "if obj is not None" to guard against a None value
+ ibis/backends/sqlite/__init__.py:535: note: You can use "if obj is not None" to guard against a None value
+ ibis/backends/clickhouse/__init__.py:681: note: You can use "if obj is not None" to guard against a None value
+ ibis/backends/materialize/__init__.py:837: note: You can use "if connector is not None" to guard against a None value

trio (https://github.com/python-trio/trio)
+ src/trio/_util.py:301: note: You can use "if agen.ag_frame is not None" to guard against a None value
+ src/trio/_core/_tests/test_asyncgen.py:309: note: You can use "if agen.ag_frame is not None" to guard against a None value
+ src/trio/_core/_tests/test_asyncgen.py:313: note: You can use "if agen.ag_frame is not None" to guard against a None value

werkzeug (https://github.com/pallets/werkzeug)
+ tests/test_wrappers.py:178: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:179: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:180: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:188: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:189: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:190: note: You can use "if a is not None" to guard against a None value
+ tests/test_wrappers.py:1060: note: You can use "if req.range is not None" to guard against a None value
+ tests/test_wrappers.py:1063: note: You can use "if req.range is not None" to guard against a None value
+ tests/test_test.py:164: note: You can use "if b.input_stream is not None" to guard against a None value
+ tests/test_test.py:166: note: You can use "if b.input_stream is not None" to guard against a None value
+ tests/test_test.py:302: note: You can use "if request.authorization is not None" to guard against a None value
+ tests/test_test.py:303: note: You can use "if request.authorization is not None" to guard against a None value
+ tests/test_routing.py:710: note: You can use "if rule.methods is not None" to guard against a None value
+ tests/test_routing.py:712: note: You can use "if rule.methods is not None" to guard against a None value
+ tests/test_local.py:191: note: You can use "if local.LocalProxy.__doc__ is not None" to guard against a None value
+ tests/test_http.py:159: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:160: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:161: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:164: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:165: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:166: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:169: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:170: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:171: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:183: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:184: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:185: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:186: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:187: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:188: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:189: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:190: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:191: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:192: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:202: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:203: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:204: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:205: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:206: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:207: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:208: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:216: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:222: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:223: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:228: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:229: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:253: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:254: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:255: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:256: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:264: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:265: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:266: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:267: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:268: note: You can use "if wa is not None" to guard against a None value
+ tests/test_http.py:277: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:278: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:283: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:284: note: You can use "if a is not None" to guard against a None value
+ tests/test_http.py:636: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:637: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:638: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:641: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:642: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:643: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:646: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:647: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:648: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:651: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:652: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:653: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:656: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:657: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:658: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:677: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:678: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:679: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:680: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:681: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:690: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:691: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:692: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:693: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:694: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:697: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:698: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:699: note: You can use "if rv is not None" to guard against a None value
+ tests/test_http.py:700: note: You can use "if rv is not None" to guard against a None value
+ tests/test_debug.py:281: note: You can use "if e.__context__ is not None" to guard against a None value
+ tests/test_datastructures.py:1108: note: You can use "if r is not None" to guard against a None value

scipy (https://github.com/scipy/scipy)
+ scipy/_lib/_array_api.py:631: note: You can use "if xp is not None" to guard against a None value
+ scipy/_lib/_array_api.py:632: note: You can use "if xp is not None" to guard against a None value
+ scipy/spatial/transform/_rigid_transform_xp.py:321: note: You can use "if indexer is not None" to guard against a None value
+ scipy/spatial/transform/_rotation.py:2222: note: You can use "if indexer is not None" to guard against a None value
+ scipy/spatial/transform/_rotation.py:2224: note: You can use "if indexer is not None" to guard against a None value
+ scipy/spatial/transform/_rigid_transform.py:1388: note: You can use "if indexer is not None" to guard against a None value
+ scipy/spatial/transform/_rigid_transform.py:1390: note: You can use "if indexer is not None" to guard against a None value

pyodide (https://github.com/pyodide/pyodide)
+ pyodide-build/pyodide_build/out_of_tree/venv.py:463: note: You can use "if self.venv_bin is not None" to guard against a None value
+ pyodide-build/pyodide_build/out_of_tree/venv.py:713: note: You can use "if self.venv_bin is not None" to guard against a None value
+ pyodide-build/pyodide_build/tests/recipe/test_unvendor.py:17: note: You can use "if test_tar_path is not None" to guard against a None value
+ pyodide-build/pyodide_build/tests/recipe/test_unvendor.py:18: note: You can use "if test_tar_path is not None" to guard against a None value
+ pyodide-build/pyodide_build/tests/recipe/test_unvendor.py:54: note: You can use "if test_tar_path is not None" to guard against a None value
+ pyodide-build/pyodide_build/tests/recipe/test_unvendor.py:55: note: You can use "if test_tar_path is not None" to guard against a None value

kornia (https://github.com/kornia/kornia)
+ kornia/enhance/histogram.py:236: note: You can use "if image is not None" to guard against a None value
+ kornia/enhance/histogram.py:239: note: You can use "if image is not None" to guard against a None value
+ kornia/enhance/histogram.py:260: note: You can use "if image is not None" to guard against a None value
+ kornia/enhance/histogram.py:263: note: You can use "if image is not None" to guard against a None value
+ kornia/enhance/histogram.py:268: note: You can use "if image is not None" to guard against a None value
+ kornia/enhance/histogram.py:270: note: You can use "if image is not None" to guard against a None value
+ kornia/models/kimi_vl/model.py:96: note: You can use "if config.vision_config is not None" to guard against a None value
+ kornia/models/siglip2/builder.py:67: note: You can use "if config.text_config is not None" to guard against a None value
+ kornia/models/siglip2/builder.py:68: note: You can use "if config.text_config is not None" to guard against a None value

apprise (https://github.com/caronc/apprise)
+ apprise/apprise_attachment.py:217: note: You can use "if instance is not None" to guard against a None value
+ apprise/apprise_attachment.py:219: note: You can use "if instance is not None" to guard against a None value
+ apprise/apprise_attachment.py:223: note: You can use "if instance is not None" to guard against a None value
+ apprise/apprise_attachment.py:224: note: You can use "if instance is not None" to guard against a None value
+ tests/test_utils_socket.py:751: note: You can use "if s._sock is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:602: note: You can use "if self.loop is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:772: note: You can use "if self.disconnected is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:773: note: You can use "if self.disconnected is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:949: note: You can use "if self.loop is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:1145: note: You can use "if self.loop is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:1233: note: You can use "if self.loop is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:2582: note: You can use "if client is not None" to guard against a None value
+ tests/test_plugin_xmpp.py:2603: note: You can use "if started is not None" to guard against a None value

materialize (https://github.com/MaterializeInc/materialize)
+ misc/python/materialize/cli/cloudbench.py:163: note: You can use "if r is not None" to guard against a None value
+ misc/python/materialize/cli/cloudbench.py:164: note: You can use "if r is not None" to guard against a None value
+ misc/python/materialize/lint/lint.py:141: note: You can use "if thread.duration is not None" to guard against a None value
+ misc/python/materialize/parallel_workload/parallel_workload.py:374: note: You can use "if worker.exe is not None" to guard against a None value

pip (https://github.com/pypa/pip)
+ src/pip/_internal/network/utils.py:65: note: You can use "if response.raw is not None" to guard against a None value
+ src/pip/_internal/network/utils.py:95: note: You can use "if response.raw is not None" to guard against a None value
+ src/pip/_internal/network/auth.py:527: note: You can use "if resp.raw is not None" to guard against a None value
+ src/pip/_internal/network/auth.py:550: note: You can use "if resp.request is not None" to guard against a None value
+ src/pip/_internal/index/collector.py:83: note: You can use "if response.request is not None" to guard against a None value

check-jsonschema (https://github.com/python-jsonschema/check-jsonschema)
+ src/check_jsonschema/cli/param_types.py:104: note: You can use "if m is not None" to guard against a None value
+ src/check_jsonschema/cli/param_types.py:105: note: You can use "if m is not None" to guard against a None value