Python team released Python versions 3.7.2rc1 and 3.6.9 rc1 yesterday. Python 3.7.2rc1 is the release preview of the second maintenance release of Python 3.7. Python. 3.6.8rc1 is the release preview of the eighth and last maintenance release of Python 3.6. These latest releases include the addition of new features.
Key Updates in Python 3.7.2rc1
- A new C API for thread-local storage has been added in Python 3.7.2rc1. A new Thread Specific Storage (TSS) API has been added to CPython which takes over the existing TLS API within the CPython interpreter while removing the existing API.
- Deterministic .pyc files have been added. These .pyc files are called “hash-based”. Python still uses timestamp-based invalidation by default and does not generate hash-based .pyc files at runtime. Hash-based .pyc files can be generated with py_compile or compileall.
- Core support added in Python 3.7.2rc1 for typing module and generic types.
- Customized access to module attributes is allowed, meaning you can now define __getattr__() on modules and can call it whenever a module attribute is not found. Defining __dir__() on modules is also allowed.
- DeprecationWarning handling has been improved.
- The insertion-order preservation nature of dict objects has now become an official part of the Python language spec.
Key Updates in Python 3.6.8rc1
- Preserving Keyword Argument order has been added in Python 3.6.9rc1, meaning that **kwargs in a function signature is now guaranteed to be an insertion-order-preserving mapping.
- Python 3.6.8rc1 offers simple customization of subclass creation without using a metaclass.The new __init_subclass__ classmethod gets called on the base class when a new subclass is created.
- A new “secrets” module has been added to the standard library that reliably generates cryptographically strong pseudo-random values suited for managing secrets like account authentication, tokens, etc.
- A frame evaluation API has been added to CPython that makes frame evaluation pluggable at the C level. This allows debuggers and JITs to intercept frame evaluation before Python code execution begins.
- Python 3.6.8rc1 offers formatted string literals or f-strings. Formatted string literals work similarly to the format strings accepted by str.format(). They comprise replacement fields that are surrounded by curly braces. The replacement fields are expressions, that are evaluated at run time, and formatted using the format() protocol.