Python 3.12+ SyntaxWarnings due to invalid escape sequences and return in finally block

Inspect the cited expressions in tos/utils.py:1155 and tos/clientv2.py:874,878. Reproduce the import under Python 3.12+ and review the surrounding try/finally flow before making the warning-related changes. Done means the import no longer emits these SyntaxWarnings and the client behavior remains covered by the existing project checks.

Description

When using tos with Python 3.12+, multiple SyntaxWarnings are emitted on import, which can be noisy in production logs.

Warnings

1. Invalid escape sequence \d in tos/utils.py:1155

p = re.compile('^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$')

Fix: Use a raw string literal:

p = re.compile(r'^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$')

2. return in finally block in tos/clientv2.py:874,878

finally:
    if len(args) <= 0 or not isinstance(args[0], TosClientV2):
        return              # line 874

    threshold = args[0].high_latency_log_threshold
    if threshold <= 0:
        return              # line 878

Having return inside a finally block overrides any exception being raised in the try or except blocks, which is likely not the intended behavior. Consider restructuring these as unconditional cleanup or moving the logic outside the finally.

Example output

.../tos/utils.py:1155: SyntaxWarning: "\d" is an invalid escape sequence. ... Did you mean "\\d"?
  p = re.compile(...)
.../tos/clientv2.py:874: SyntaxWarning: 'return' in a 'finally' block
  return
.../tos/clientv2.py:878: SyntaxWarning: 'return' in a 'finally' block
  return

Environment

• tos version: 2.9.2
• Python: 3.12+
• OS: macOS

These warnings are visible by default since Python 3.12, where DeprecationWarning for invalid escape sequences was upgraded to SyntaxWarning.