The best new features in Python 3.15

Transformative new Python features are coming in Python 3.15. In addition to lazy imports and an immutable frozendict type, the new Python release will deliver significant improvements to the native JIT compiler and introduce a more explicit agenda for how Python will support WebAssembly. Top picks for Python readers on InfoWorld Speed-boost your Python programs with the new lazy imports feature Starting with Python 3.15, Python imports can work lazily, deferring the cost of loading big libraries. And you don’t have to rewrite your Python apps to use it. How Python is getting serious about Wasm Python is slowly but surely becoming a first-class citizen in the WebAssembly world. A new Python Enhancement Proposal, PEP 816, describes how that will happen. Get started with Python’s new frozendict type A new immutable dictionary type in Python 3.15 fills a long-desired niche in Python — and can be used in more places than ordinary dictionaries. How to use Python dataclasses Python dataclass

Only very rarely does Python add a new standard data type. Python 3.15, when it’s released later this year, will come with one—an immutable dictionary, frozendict. Dictionaries in Python correspond to hashmaps in Java. They are a way to associate keys with values. The Python dict, as it’s called, is tremendously powerful and versatile. In fact, the dict structure is used by the CPython interpreter to handle many things internally. But a dict has a big limitation: it’s not hashable. A hashable type in Python has a hash value that never changes during its lifetime. Strings, numerical values (integers and floats), and tuples are all hashable because they are immutable. Container types, like lists, sets, and, yes, dicts, are mutable, so can’t guarantee they hold the same values over time. Python has long included a frozenset type—a version of a set that doesn’t change over its lifetime and is hashable. Because sets are basically dictionaries with keys and no values, why not also have a fro