PY-COLL0003 · evidence

This page continues PY-COLL0003 directly from its source docstring. Read its implementation.

Evidence

Each finding names the local binding, the form it is written as, how many values it holds, and which of the two proofs its reads satisfy. The rule reports a candidate without a fix because public annotations and downstream behavior can still impose a contract outside the function. The value is the number of local collections whose proven use fixes a clearer representation.

Exceptions

Annotated values, module constants, returned values, escaped arguments, indexing, unpacking, equality, mutation, duplicate membership values, heterogeneous tuples, hash keys, and unknown uses are excluded, and so is a name the callable rebinds, since the second binding may hold anything. Fixed heterogeneous records remain tuples. Frozen snapshots and hashable keys remain tuples or frozen sets even when the project generally prefers lists. sequence_preference is the form an iteration-only literal is recommended as, defaulting to a list, and setting prefer_membership_set to false leaves a membership-only literal alone for a project that would rather keep its order.

References

• Cites “Fluent Python”, chapter 2, sequences
• Cites “The Python Tutorial”, data structures. Open reference
• Cites “The Python Language Reference”, standard type hierarchy. Open reference