[aclark4life]

PYTHON-6274

Changes in this PR

Enable ruff PLR2004 and replace magic numbers in comparisons with named constants in bson/, pymongo/, .evergreen/scripts/, and tools/.

Tests keep the rule disabled through per-file ignores, because expected literals in tests are the specification.

Test Plan

• ruff check . and ruff format --check .
• just typing
• Targeted pytest runs: bson, binary, decimal128, objectid, json_util, uri_parser, network layer, compression, sessions, and SRV polling.

Checklist

Checklist for Author

• Did you update the changelog (if necessary)?
• Is there test coverage?
• Is any followup work tracked in a JIRA ticket? If so, add link(s).

Checklist for Reviewer

• Does the title of the PR reference a JIRA Ticket?
• Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
• Is all relevant documentation (README or docstring) updated?

[Copilot]

🟡 Changes recommended

The timezone-offset length constants misleadingly describe the supported formats and need names and references that accurately distinguish ±HH:MM from ±HHMM.

1 open issue

• Name timezone offset length constants by supported syntax · New

What changed in this PR

This PR enables Ruff’s PLR2004 rule and replaces numeric comparison literals with named constants across BSON, the driver, and supporting scripts, without intending to change runtime behavior.

Changes:

• Enables the rule while exempting files under test/.
• Names protocol sizes, validation bounds, server feature thresholds, and error codes, including generated synchronous counterparts.
• Preserves literal tuple-length checks needed for type narrowing through targeted suppressions.

File	Description
tools/​compare_import_time.py	Names the import-time regression threshold.
pyproject.toml	Enables PLR2004 and adds test exemptions.
pymongo/​uri_parser_shared.py	Names the maximum port value.
pymongo/​topology_description.py	Uses the MongoDB 6.0 wire-version constant.
pymongo/​synchronous/​srv_resolver.py	Mirrors DNS label-count constants.
pymongo/​synchronous/​encryption.py	Mirrors the encrypted subtype constant.
pymongo/​synchronous/​collection.py	Mirrors feature-gate and error-code constants.
pymongo/​synchronous/​client_bulk.py	Mirrors the bulk-write wire-version constant.
pymongo/​synchronous/​bulk.py	Mirrors the update-sort wire-version constant.
pymongo/​synchronous/​auth.py	Mirrors the minimum SCRAM iteration constant.
pymongo/​server_description.py	Names the retryable-read wire-version threshold.
pymongo/​read_preferences.py	Names the secondary aggregation-write threshold.
pymongo/​ocsp_support.py	Names the successful HTTP status code.
pymongo/​network_layer.py	Names message-header sizes and compression opcode.
pymongo/​mongo_client_shared.py	Reuses the MMAPv1 transaction error constant.
pymongo/​helpers_shared.py	Names command and write error codes.
pymongo/​errors.py	Defines shared server error-code constants.
pymongo/​cursor_shared.py	Exempts a tuple-length check for type narrowing.
pymongo/​compression_support.py	Names the maximum zlib compression level.
pymongo/​common.py	Adds wire-version and validation constants.
pymongo/​client_session_shared.py	Uses timeout and snapshot-read constants.
pymongo/​bulk_shared.py	Reuses the MMAPv1 transaction error constant.
pymongo/​asynchronous/​srv_resolver.py	Names DNS label-count thresholds.
pymongo/​asynchronous/​encryption.py	Names the encrypted BSON subtype.
pymongo/​asynchronous/​collection.py	Uses feature-gate and namespace-error constants.
pymongo/​asynchronous/​client_bulk.py	Uses the bulk-write wire-version constant.
pymongo/​asynchronous/​bulk.py	Uses the update-sort wire-version constant.
pymongo/​asynchronous/​auth.py	Names the minimum SCRAM iteration count.
pymongo/​_kms_connect_shared.py	Names HTTP validation and relay-completion constants.
pymongo/​_gcp_helpers.py	Names the successful HTTP status code.
pymongo/​_client_bulk_shared.py	Reuses the MMAPv1 transaction error constant.
pymongo/​_azure_helpers.py	Names the successful HTTP status code.
bson/​objectid.py	Names binary and hexadecimal ObjectId lengths.
bson/​json_util.py	Names Extended JSON format lengths and counts.
bson/​decimal128.py	Names byte length and preserves tuple narrowing.
bson/​binary.py	Names subtype, UUID, vector, and padding bounds.
bson/​__init__.py	Names integer/document bounds and reuses a subtype constant.
.evergreen/​scripts/​test_generate_config.py	Names task-count expectations.
.evergreen/​scripts/​setup_tests.py	Names the successful download status code.
.evergreen/​scripts/​mod_wsgi_matrix.py	Names the expected command-line argument count.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the PLR2004 and named-constant changes.

No open issues 🎉

1 resolved since last review

• Name timezone offset length constants by supported syntax

_{Review effort: Balanced}