Add note for union types with missing attribute

[Prabhat-Thapa45]

This pull request fixes an issue #17036

If some attribute is not defined for a single union item (often None), this helps new users to narrow down by providing hint.
For example, the following code:

class A:
    def foo(self) -> int: pass

def f(x: Union[A, None]) -> int:
    return x.foo()

previously (on the master branch) generated this error message:

main.py:8: error: Item "B" of "A | B" has no attribute "x" [union-attr]

With this PR, the message remains, but we add a suggestion for how to fix the error:

main.py:8: error: Item "B" of "A | B" has no attribute "x"  [union-attr]
main.py:8: note: You can use 'if hasattr( a, 'x'):' to guard against missing attribute error

[github-actions]

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

check-jsonschema (https://github.com/python-jsonschema/check-jsonschema)
+ src/check_jsonschema/cli/param_types.py:90: note: You can use 'if hasattr( m, 'group'):' to guard against missing attribute error
+ src/check_jsonschema/cli/param_types.py:91: note: You can use 'if hasattr( m, 'group'):' to guard against missing attribute error

Tanjun (https://github.com/FasterSpeeding/Tanjun)
+ tanjun/dependencies/limiters.py:819: note: You can use 'if hasattr( resource, 'check'):' to guard against missing attribute error

cki-lib (https://gitlab.com/cki-project/cki-lib)
+ cki_lib/s3bucket.py:57: note: You can use 'if hasattr( boto3.DEFAULT_SESSION, 'get_credentials'):' to guard against missing attribute error
+ tests/test_cronjob.py:83: note: You can use 'if hasattr( runner, 'join'):' to guard against missing attribute error
+ tests/test_cronjob.py:109: note: You can use 'if hasattr( runner, 'join'):' to guard against missing attribute error
+ tests/test_cronjob.py:117: note: You can use 'if hasattr( runner, 'join'):' to guard against missing attribute error
+ tests/test_cronjob.py:127: note: You can use 'if hasattr( runner, 'join'):' to guard against missing attribute error

spack (https://github.com/spack/spack)
+ lib/spack/spack/util/spack_yaml.py:505: note: You can use 'if hasattr( <variable name>, '__next__'):' to guard against missing attribute error

operator (https://github.com/canonical/operator)
+ ops/lib/__init__.py:273: note: You can use 'if hasattr( self.spec.loader, 'exec_module'):' to guard against missing attribute error

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/indexing.py:912: note: You can use 'if hasattr( iloc, '_setitem_with_indexer'):' to guard against missing attribute error

aioredis (https://github.com/aio-libs/aioredis)
+ aioredis/connection.py:934: note: You can use 'if hasattr( <variable name>, 'split'):' to guard against missing attribute error

pip (https://github.com/pypa/pip)
+ src/pip/_internal/metadata/pkg_resources.py:182: note: You can use 'if hasattr( self._dist._provider, 'path'):' to guard against missing attribute error
+ src/pip/_internal/network/utils.py:65: note: You can use 'if hasattr( response.raw, 'stream'):' to guard against missing attribute error
+ src/pip/_internal/network/utils.py:95: note: You can use 'if hasattr( response.raw, 'read'):' to guard against missing attribute error
+ src/pip/_internal/network/auth.py:525: note: You can use 'if hasattr( resp.raw, 'release_conn'):' to guard against missing attribute error
+ src/pip/_internal/network/auth.py:548: note: You can use 'if hasattr( resp.request, 'url'):' to guard against missing attribute error
+ src/pip/_internal/network/session.py:408: note: You can use 'if hasattr( self.auth, 'index_urls'):' to guard against missing attribute error
+ src/pip/_internal/index/collector.py:88: note: You can use 'if hasattr( response.request, 'method'):' to guard against missing attribute error
+ src/pip/_internal/cli/index_command.py:128: note: You can use 'if hasattr( session.auth, 'prompting'):' to guard against missing attribute error
+ src/pip/_internal/cli/index_command.py:129: note: You can use 'if hasattr( session.auth, 'keyring_provider'):' to guard against missing attribute error

sphinx (https://github.com/sphinx-doc/sphinx)
+ sphinx/builders/html/__init__.py:448:16: note: You can use 'if hasattr( self._publisher.writer, 'parts'):' to guard against missing attribute error

dd-trace-py (https://github.com/DataDog/dd-trace-py)
+ ddtrace/internal/gitmetadata.py:77: note: You can use 'if hasattr( <variable name>, '__iter__'):' to guard against missing attribute error

ibis (https://github.com/ibis-project/ibis)
+ ibis/common/dispatch.py:34: note: You can use 'if hasattr( r, 'lstrip'):' to guard against missing attribute error
+ ibis/expr/datatypes/cast.py:20: note: You can use 'if hasattr( source, 'castable'):' to guard against missing attribute error
+ ibis/selectors.py:394: note: You can use 'if hasattr( self.funcs, 'items'):' to guard against missing attribute error
+ ibis/selectors.py:607: note: You can use 'if hasattr( key, '__iter__'):' to guard against missing attribute error
+ ibis/selectors.py:610: note: You can use 'if hasattr( key, 'start'):' to guard against missing attribute error
+ ibis/selectors.py:611: note: You can use 'if hasattr( key, 'stop'):' to guard against missing attribute error
+ ibis/selectors.py:612: note: You can use 'if hasattr( key, 'step'):' to guard against missing attribute error
+ ibis/expr/types/generic.py:1243: note: You can use 'if hasattr( data_mapper, 'convert_scalar'):' to guard against missing attribute error
+ ibis/expr/types/generic.py:1417: note: You can use 'if hasattr( data_mapper, 'convert_column'):' to guard against missing attribute error
+ ibis/expr/types/maps.py:498: note: You can use 'if hasattr( keys, 'keys'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:202: note: You can use 'if hasattr( data_mapper, 'convert_table'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:461: note: You can use 'if hasattr( schema, 'names'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:467: note: You can use 'if hasattr( schema, 'get'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:1116: note: You can use 'if hasattr( metrics, 'values'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:1117: note: You can use 'if hasattr( metrics, 'copy'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:1118: note: You can use 'if hasattr( having, '__iter__'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:3964: note: You can use 'if hasattr( match_result, 'groups'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:4379: note: You can use 'if hasattr( names, 'sort_values'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:4379: note: You can use 'if hasattr( names, 'columns'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:4385: note: You can use 'if hasattr( names, 'columns'):' to guard against missing attribute error
+ ibis/expr/types/relations.py:4387: note: You can use 'if hasattr( names, 'itertuples'):' to guard against missing attribute error
+ ibis/expr/types/json.py:230: note: You can use 'if hasattr( dtype, 'is_string'):' to guard against missing attribute error
+ ibis/expr/types/json.py:232: note: You can use 'if hasattr( dtype, 'is_boolean'):' to guard against missing attribute error
+ ibis/expr/types/json.py:234: note: You can use 'if hasattr( dtype, 'is_integer'):' to guard against missing attribute error
+ ibis/expr/types/json.py:237: note: You can use 'if hasattr( dtype, 'is_floating'):' to guard against missing attribute error
+ ibis/expr/types/json.py:240: note: You can use 'if hasattr( dtype, 'is_map'):' to guard against missing attribute error
+ ibis/expr/types/json.py:243: note: You can use 'if hasattr( dtype, 'is_array'):' to guard against missing attribute error
+ ibis/backends/sql/datatypes.py:1092: note: You can use 'if hasattr( scale, 'this'):' to guard against missing attribute error
+ ibis/backends/tests/base.py:108: note: You can use 'if hasattr( <variable name>, '__file__'):' to guard against missing attribute error
+ ibis/backends/sql/compilers/base.py:1124: note: You can use 'if hasattr( op, '__func_name__'):' to guard against missing attribute error
+ ibis/backends/sql/compilers/base.py:1125: note: You can use 'if hasattr( op, '__input_type__'):' to guard against missing attribute error
+ ibis/backends/sql/compilers/base.py:1131: note: You can use 'if hasattr( op, '__udf_namespace__'):' to guard against missing attribute error
+ ibis/examples/gen_registry.py:329: note: You can use 'if hasattr( <variable name>, 'get'):' to guard against missing attribute error
+ ibis/backends/sql/compilers/pyspark.py:315: note: You can use 'if hasattr( op, '__func__'):' to guard against missing attribute error
+ ibis/backends/sql/compilers/pyspark.py:316: note: You can use 'if hasattr( op, '__func_name__'):' to guard against missing attribute error
+ ibis/backends/druid/tests/conftest.py:87: note: You can use 'if hasattr( match, 'groupdict'):' to guard against missing attribute error
+ ibis/backends/trino/__init__.py:59: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/snowflake/__init__.py:759: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/snowflake/__init__.py:766: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/pyspark/__init__.py:404: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/postgres/__init__.py:800: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/oracle/__init__.py:222: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/mysql/__init__.py:278: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/mssql/__init__.py:308: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/duckdb/__init__.py:95: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/datafusion/__init__.py:224: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error
+ ibis/backends/datafusion/__init__.py:319: note: You can use 'if hasattr( catalog, 'database'):' to guard against missing attribute error
+ ibis/backends/datafusion/__init__.py:321: note: You can use 'if hasattr( catalog, 'database'):' to guard against missing attribute error
+ ibis/backends/datafusion/__init__.py:323: note: You can use 'if hasattr( database, 'table'):' to guard against missing attribute error
+ ibis/backends/clickhouse/__init__.py:267: note: You can use 'if hasattr( expr, 'op'):' to guard against missing attribute error
+ ibis/backends/clickhouse/__init__.py:466: note: You can use 'if hasattr( query, 'sql'):' to guard against missing attribute error

urllib3 (https://github.com/urllib3/urllib3)
+ test/with_dummyserver/test_proxy_poolmanager.py:52: note: You can use 'if hasattr( connection, 'proxy_is_verified'):' to guard against missing attribute error
+ test/with_dummyserver/test_proxy_poolmanager.py:53: note: You can use 'if hasattr( connection, 'is_verified'):' to guard against missing attribute error

spark (https://github.com/apache/spark)
+ python/pyspark/sql/pandas/conversion.py:404: note: You can use 'if hasattr( data, 'columns'):' to guard against missing attribute error

rich (https://github.com/Textualize/rich)
+ rich/console.py:92: note: You can use 'if hasattr( sys.__stdin__, 'fileno'):' to guard against missing attribute error
+ rich/console.py:96: note: You can use 'if hasattr( sys.__stdout__, 'fileno'):' to guard against missing attribute error
+ rich/console.py:100: note: You can use 'if hasattr( sys.__stderr__, 'fileno'):' to guard against missing attribute error

pytest (https://github.com/pytest-dev/pytest)
+ testing/_py/test_local.py:860: note: You can use 'if hasattr( x, 'check'):' to guard against missing attribute error
+ testing/_py/test_local.py:863: note: You can use 'if hasattr( x, 'dirpath'):' to guard against missing attribute error
+ testing/_py/test_local.py:914: note: You can use 'if hasattr( x, 'check'):' to guard against missing attribute error
+ testing/_py/test_local.py:916: note: You can use 'if hasattr( y, 'check'):' to guard against missing attribute error
+ testing/_py/test_local.py:925: note: You can use 'if hasattr( x, 'basename'):' to guard against missing attribute error
+ testing/_py/test_local.py:926: note: You can use 'if hasattr( x, 'dirpath'):' to guard against missing attribute error
+ testing/_py/test_local.py:931: note: You can use 'if hasattr( x, 'sysexec'):' to guard against missing attribute error
+ testing/_py/test_local.py:942: note: You can use 'if hasattr( x, 'sysexec'):' to guard against missing attribute error
+ testing/_py/test_local.py:1283: note: You can use 'if hasattr( cmd, 'new'):' to guard against missing attribute error
+ testing/_py/test_local.py:1285: note: You can use 'if hasattr( cmd, 'relto'):' to guard against missing attribute error
+ testing/_py/test_local.py:1286: note: You can use 'if hasattr( x, 'check'):' to guard against missing attribute error

dragonchain (https://github.com/dragonchain/dragonchain)
+ dragonchain/broadcast_processor/broadcast_functions.py:95:32: note: You can use 'if hasattr( <variable name>, 'group'):' to guard against missing attribute error
+ dragonchain/lib/authorization.py:315:19: note: You can use 'if hasattr( <variable name>, 'group'):' to guard against missing attribute error
+ dragonchain/lib/authorization.py:317:25: note: You can use 'if hasattr( <variable name>, 'group'):' to guard against missing attribute error
+ dragonchain/lib/authorization.py:340:31: note: You can use 'if hasattr( <variable name>, 'group'):' to guard against missing attribute error

discord.py (https://github.com/Rapptz/discord.py)
+ discord/mentions.py:126: note: You can use 'if hasattr( self, '__iter__'):' to guard against missing attribute error
+ discord/mentions.py:131: note: You can use 'if hasattr( self, '__iter__'):' to guard against missing attribute error
+ discord/invite.py:466: note: You can use 'if hasattr( guild, 'get_channel'):' to guard against missing attribute error
+ discord/poll.py:385: note: You can use 'if hasattr( question_data, 'get'):' to guard against missing attribute error
+ discord/guild.py:3220: note: You can use 'if hasattr( channel, 'id'):' to guard against missing attribute error
+ discord/app_commands/commands.py:234: note: You can use 'if hasattr( callback, 'pass_command_binding'):' to guard against missing attribute error
+ discord/app_commands/commands.py:682: note: You can use 'if hasattr( callback, '__self__'):' to guard against missing attribute error
+ discord/app_commands/commands.py:683: note: You can use 'if hasattr( callback, '__func__'):' to guard against missing attribute error
+ discord/app_commands/commands.py:2469: note: You can use 'if hasattr( func, '__discord_app_commands_checks__'):' to guard against missing attribute error
+ discord/app_commands/commands.py:2471: note: You can use 'if hasattr( func, '__discord_app_commands_checks__'):' to guard against missing attribute error
+ discord/ext/commands/core.py:430: note: You can use 'if hasattr( func, '__commands_checks__'):' to guard against missing attribute error
+ discord/ext/commands/core.py:438: note: You can use 'if hasattr( func, '__commands_cooldown__'):' to guard against missing attribute error
+ discord/ext/commands/core.py:451: note: You can use 'if hasattr( func, '__commands_max_concurrency__'):' to guard against missing attribute error
+ discord/ext/commands/core.py:468: note: You can use 'if hasattr( func, '__before_invoke__'):' to guard against missing attribute error
+ discord/ext/commands/core.py:476: note: You can use 'if hasattr( func, '__after_invoke__'):' to guard against missing attribute error
+ discord/ext/commands/hybrid.py:309: note: You can use 'if hasattr( wrapped.callback, '__signature__'):' to guard against missing attribute error
+ discord/ext/commands/hybrid.py:319: note: You can use 'if hasattr( wrapped.callback, '__signature__'):' to guard against missing attribute error

xarray (https://github.com/pydata/xarray)
+ xarray/plot/facetgrid.py:720: note: You can use 'if hasattr( self._hue_var, 'to_numpy'):' to guard against missing attribute error

core (https://github.com/home-assistant/core)
+ homeassistant/components/linear_garage_door/coordinator.py:56: note: You can use 'if hasattr( self, '__iter__'):' to guard against missing attribute error
+ homeassistant/components/file_upload/__init__.py:187: note: You can use 'if hasattr( fut, 'done'):' to guard against missing attribute error

steam.py (https://github.com/Gobot1234/steam.py)
+ steam/id.py:558: note: You can use 'if hasattr( session, 'get'):' to guard against missing attribute error

prefect (https://github.com/PrefectHQ/prefect)
+ src/prefect/utilities/dispatch.py:191: note: You can use 'if hasattr( registry, 'get'):' to guard against missing attribute error
+ src/prefect/utilities/collections.py:185: note: You can use 'if hasattr( types, '__iter__'):' to guard against missing attribute error
+ src/prefect/server/schemas/states.py:273: note: You can use 'if hasattr( self.name, 'lower'):' to guard against missing attribute error
+ src/prefect/utilities/templating.py:345: note: You can use 'if hasattr( client, 'read_variable_by_name'):' to guard against missing attribute error
+ src/prefect/utilities/templating.py:354: note: You can use 'if hasattr( client, 'read_variable_by_name'):' to guard against missing attribute error
+ src/prefect/utilities/importtools.py:166: note: You can use 'if hasattr( spec, 'loader'):' to guard against missing attribute error
+ src/prefect/utilities/importtools.py:166: note: You can use 'if hasattr( spec.loader, 'exec_module'):' to guard against missing attribute error
+ src/prefect/utilities/importtools.py:341: note: You can use 'if hasattr( real_spec, 'origin'):' to guard against missing attribute error
+ src/prefect/utilities/importtools.py:342: note: You can use 'if hasattr( real_spec, 'submodule_search_locations'):' to guard against missing attribute error
+ src/prefect/client/subscriptions.py:30: note: You can use 'if hasattr( base_url, 'replace'):' to guard against missing attribute error
+ src/prefect/client/schemas/objects.py:388: note: You can use 'if hasattr( self.name, 'lower'):' to guard against missing attribute error
+ src/prefect/_internal/concurrency/services.py:193: note: You can use 'if hasattr( self._done_event, 'is_set'):' to guard against missing attribute error
+ src/prefect/_internal/concurrency/services.py:198: note: You can use 'if hasattr( self._done_event, 'wait'):' to guard against missing attribute error
+ src/prefect/client/base.py:297: note: You can use 'if hasattr( response, 'status_code'):' to guard against missing attribute error
+ src/prefect/client/base.py:511: note: You can use 'if hasattr( response, 'status_code'):' to guard against missing attribute error
+ src/prefect/variables.py:72: note: You can use 'if hasattr( variable, 'value'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:80: note: You can use 'if hasattr( schema.block_type, 'slug'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:782: note: You can use 'if hasattr( client, 'read_block_document_by_name'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:1021: note: You can use 'if hasattr( client, 'create_block_document'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:1028: note: You can use 'if hasattr( client, 'read_block_document_by_name'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:1032: note: You can use 'if hasattr( client, 'update_block_document'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:1038: note: You can use 'if hasattr( client, 'read_block_document'):' to guard against missing attribute error
+ src/prefect/blocks/core.py:1084: note: You can use 'if hasattr( client, 'delete_block_document'):' to guard against missing attribute error
+ src/prefect/runner/storage.py:293: note: You can use 'if hasattr( <variable name>, 'get_block_placeholder'):' to guard against missing attribute error
+ src/prefect/client/orchestration.py:3205: note: You can use 'if hasattr( id_or_name, 'lower'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:415: note: You can use 'if hasattr( value, '__iter__'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:898: note: You can use 'if hasattr( image, 'reference'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:903: note: You can use 'if hasattr( image, 'build'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:907: note: You can use 'if hasattr( image, 'reference'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:919: note: You can use 'if hasattr( image, 'push'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:923: note: You can use 'if hasattr( image, 'reference'):' to guard against missing attribute error
+ src/prefect/deployments/runner.py:927: note: You can use 'if hasattr( image, 'reference'):' to guard against missing attribute error
+ src/prefect/utilities/urls.py:169: note: You can use 'if hasattr( obj, '_block_document_id'):' to guard against missing attribute error
+ src/prefect/utilities/urls.py:171: note: You can use 'if hasattr( obj, 'name'):' to guard against missing attribute error
+ src/prefect/utilities/urls.py:187: note: You can use 'if hasattr( url_format, 'format'):' to guard against missing attribute error
+ src/prefect/utilities/urls.py:191: note: You can use 'if hasattr( url_format, 'format'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:263: note: You can use 'if hasattr( <variable name>, 'data'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:288: note: You can use 'if hasattr( self.session, 'add'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:291: note: You can use 'if hasattr( self.session, 'flush'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:417: note: You can use 'if hasattr( <variable name>, 'data'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:447: note: You can use 'if hasattr( self.session, 'add'):' to guard against missing attribute error
+ src/prefect/server/orchestration/rules.py:450: note: You can use 'if hasattr( self.session, 'flush'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:187: note: You can use 'if hasattr( full_child_block_document, 'data'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:195: note: You can use 'if hasattr( full_child_block_document, 'block_document_references'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:310: note: You can use 'if hasattr( sort, 'as_sql_sort'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:369: note: You can use 'if hasattr( sort, 'as_sql_sort'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:407: note: You can use 'if hasattr( block_document, 'block_schema_id'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:418: note: You can use 'if hasattr( block_document, 'block_schema_id'):' to guard against missing attribute error
+ src/prefect/server/models/block_documents.py:420: note: You can use 'if hasattr( block_document, 'block_schema'):' to guard against missing attribute error
+ src/prefect/server/orchestration/instrumentation_policies.py:38: note: You can use 'if hasattr( context.initial_state, 'timestamp'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:80: note: You can use 'if hasattr( context.proposed_state, 'type'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:93: note: You can use 'if hasattr( context.proposed_state, 'name'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:106: note: You can use 'if hasattr( context.proposed_state, 'is_running'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:108: note: You can use 'if hasattr( context.proposed_state, 'timestamp'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:121: note: You can use 'if hasattr( context.proposed_state, 'timestamp'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:141: note: You can use 'if hasattr( context.proposed_state, 'is_final'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:147: note: You can use 'if hasattr( context.proposed_state, 'is_final'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:150: note: You can use 'if hasattr( context.proposed_state, 'timestamp'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:166: note: You can use 'if hasattr( context.proposed_state, 'timestamp'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:180: note: You can use 'if hasattr( context.proposed_state, 'is_running'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:204: note: You can use 'if hasattr( proposed_state, 'is_running'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:204: note: You can use 'if hasattr( proposed_state, 'is_final'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:221: note: You can use 'if hasattr( context.proposed_state, 'is_running'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:240: note: You can use 'if hasattr( context.proposed_state, 'is_scheduled'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:242: note: You can use 'if hasattr( context.proposed_state, 'state_details'):' to guard against missing attribute error
+ src/prefect/server/orchestration/global_policy.py:245: note: You can use 'if hasattr( context.proposed_state, 'timestamp'):' to guard against missing attribute error

... (truncated 177 lines) ...

materialize (https://github.com/MaterializeInc/materialize)
+ misc/python/materialize/mzcompose/services/materialized.py:99: note: You can use 'if hasattr( system_parameter_defaults, 'update'):' to guard against missing attribute error
+ misc/python/materialize/mzcompose/services/materialized.py:105: note: You can use 'if hasattr( system_parameter_defaults, 'items'):' to guard against missing attribute error
+ misc/python/materialize/lint/lint.py:136: note: You can use 'if hasattr( thread.duration, 'total_seconds'):' to guard against missing attribute error
+ ci/mkpipeline.py:464: note: You can use 'if hasattr( step, 'get'):' to guard against missing attribute error
+ misc/python/materialize/parallel_workload/parallel_workload.py:356: note: You can use 'if hasattr( worker.exe, 'last_log'):' to guard against missing attribute error
+ misc/python/materialize/cli/cloudbench.py:163: note: You can use 'if hasattr( r, 'fieldnames'):' to guard against missing attribute error
+ misc/python/materialize/cli/cloudbench.py:164: note: You can use 'if hasattr( r, 'fieldnames'):' to guard against missing attribute error

mitmproxy (https://github.com/mitmproxy/mitmproxy)
+ web/gen/tflow_js.py:31: note: You can use 'if hasattr( tf_http.response, 'trailers'):' to guard against missing attribute error

kornia (https://github.com/kornia/kornia)
+ kornia/enhance/histogram.py:217: note: You can use 'if hasattr( image, 'device'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:217: note: You can use 'if hasattr( image, 'dtype'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:220: note: You can use 'if hasattr( image, 'unsqueeze'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:241: note: You can use 'if hasattr( image, 'dim'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:244: note: You can use 'if hasattr( image, 'dim'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:249: note: You can use 'if hasattr( image, 'dim'):' to guard against missing attribute error
+ kornia/enhance/histogram.py:251: note: You can use 'if hasattr( image, 'dim'):' to guard against missing attribute error

werkzeug (https://github.com/pallets/werkzeug)
+ tests/test_wrappers.py:179: note: You can use 'if hasattr( a, 'type'):' to guard against missing attribute error
+ tests/test_wrappers.py:180: note: You can use 'if hasattr( a, 'username'):' to guard against missing attribute error
+ tests/test_wrappers.py:181: note: You can use 'if hasattr( a, 'password'):' to guard against missing attribute error
+ tests/test_wrappers.py:189: note: You can use 'if hasattr( a, 'type'):' to guard against missing attribute error
+ tests/test_wrappers.py:190: note: You can use 'if hasattr( a, 'username'):' to guard against missing attribute error
+ tests/test_wrappers.py:191: note: You can use 'if hasattr( a, 'password'):' to guard against missing attribute error
+ tests/test_wrappers.py:1078: note: You can use 'if hasattr( req.range, 'ranges'):' to guard against missing attribute error
+ tests/test_wrappers.py:1081: note: You can use 'if hasattr( req.range, 'make_content_range'):' to guard against missing attribute error
+ tests/test_test.py:166: note: You can use 'if hasattr( b.input_stream, 'getvalue'):' to guard against missing attribute error
+ tests/test_test.py:168: note: You can use 'if hasattr( b.input_stream, 'getvalue'):' to guard against missing attribute error
+ tests/test_test.py:306: note: You can use 'if hasattr( request.authorization, 'username'):' to guard against missing attribute error

... (truncated 149 lines) ...```

[JelleZijlstra]

I don't think we should encourage hasattr() checks. This adds an attribute of type Any, not something we should encourage.

[Prabhat-Thapa45]

#17036

@JelleZijlstra could you please explain by it adds attribute of type Any. As far as I understood it only checks if an object has a specific attribute. Am i missing something but I can change it to isinstance() one

[JelleZijlstra]

https://mypy-play.net/?mypy=latest&python=3.12&gist=9bcc9b1ea9eb782372d7662fe53b2c5d