uniqlo-sales-alerter python-standards.instructions.md

Python Standards

Naming

• Avoid single-letter variables outside list comprehensions and lambdas.
• Use descriptive names: safe_title not t, color_display_code not cd.
• Abbreviations pid (product ID), pg (price group), wv (watched variant) are acceptable as they are domain-standard in this codebase.

Constants

• Extract magic strings and numbers into module-level constants (e.g. _STOCK_OUT, _DEFAULT_PRICE_GROUP, _SMTP_TIMEOUT).
• Use frozenset for immutable sets of valid values.

Documentation

• All public classes and functions must have docstrings.
• Private helpers (_name) should have docstrings if their purpose isn't obvious from the name.
• Do NOT add comments that narrate what the code does. Comments should explain why.

Logging

• Use logger for diagnostic output, not print().
• Exception: print() is acceptable for intentional user-facing console output (rate-limit warnings, CLI preview).

Error handling

• Prefer specific exception types over bare except Exception.
• When a missing optional dependency is detected, be consistent: log and return (like Telegram) or raise with a clear message (like email). Don't mix approaches for the same severity.

Pydantic models

• All model classes need a class docstring.
• Use Field(default_factory=...) for mutable defaults, never = [] or = {}.