PyTuple

PyTuple is a Python library that provides an immutable, tuple-like data structure designed for safe, functional-style programming and interoperation with Python's existing sequence types. The core type, PyTuple, behaves like a Python tuple but emphasizes immutability and structural sharing to support large, read-only datasets without duplicating substructures.

Design and characteristics: PyTuple stores its elements in a fixed-length sequence; elements can be any Python object; the type is hashable when all elements are hashable; slicing returns another PyTuple; it implements the sequence protocol, so indexing, iteration, and length work as with built-in tuples; equality conforms to element-wise equality; representation prints like PyTuple([1, 2, 3]).

API and usage: Creation: PyTuple.from_iterable(iterable) or PyTuple([a, b, c]); immutability means methods that would modify the tuple instead return a new PyTuple. Common operations include append, concat, replace(index, value), and slice(start, end). Interoperability: many built-ins accept PyTuple where tuples are expected; can be converted to a built-in tuple with to_tuple().

Performance and limitations: immutability helps with correctness and thread safety; performance depends on usage; for small sequences there may be overhead compared with plain tuple; not yet as widely adopted; best for functional pipelines or persistent data structures where sharing substructures is beneficial.

See also: Python tuple, persistent data structure, typed tuples, functional programming utilities.