Release date: Nov. 3, 2020

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This releasee, 3.10.0a2 is the second of six planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

• PEP 623 -- Remove wstr from Unicode
• PEP 604 -- Allow writing union types as X | Y
• PEP 612 -- Parameter Specification Variables
• PEP 626 -- Precise line numbers for debugging and other tools.
• bpo-38605: from __future__ import annotations (PEP 563) is now the default.

• PEP 618 -- Add Optional Length-Checking To zip.

• (Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0a3, currently scheduled for 2020-12-07.

More resources

• Online Documentation
• PEP 619, 3.10 Release Schedule
• Report bugs at https://bugs.python.org.
• Help fund Python and its community.

And now for something completely different

The cardinality (the number of elements) of infinite sets can be one of the most surprising results of set theory. For example, there are the same amount of even natural numbers than natural numbers (which can be even or odd). There is also the same amount of rational numbers than natural numbers. But on the other hand, there are more real numbers between 0 and 1 than natural numbers! All these sets have infinite cardinality but turn out that some of these infinities are bigger than others. These infinite cardinalities normally are represented using aleph numbers. Infinite sets are strange beasts indeed.