This is the initial implementation of PEP 615, the zoneinfo module,
ported from the standalone reference implementation (see
https://www.python.org/dev/peps/pep-0615/#reference-implementation for a
link, which has a more detailed commit history).
This includes (hopefully) all functional elements described in the PEP,
but documentation is found in a separate PR. This includes:
1. A pure python implementation of the ZoneInfo class
2. A C accelerated implementation of the ZoneInfo class
3. Tests with 100% branch coverage for the Python code (though C code
coverage is less than 100%).
4. A compile-time configuration option on Linux (though not on Windows)
Differences from the reference implementation:
- The module is arranged slightly differently: the accelerated module is
`_zoneinfo` rather than `zoneinfo._czoneinfo`, which also necessitates
some changes in the test support function. (Suggested by Victor
Stinner and Steve Dower.)
- The tests are arranged slightly differently and do not include the
property tests. The tests live at test/test_zoneinfo/test_zoneinfo.py
rather than test/test_zoneinfo.py or test/test_zoneinfo/__init__.py
because we may do some refactoring in the future that would likely
require this separation anyway; we may:
- include the property tests
- automatically run all the tests against both pure Python and C,
rather than manually constructing C and Python test classes (similar
to the way this works with test_datetime.py, which generates C
and Python test cases from datetimetester.py).
- This includes a compile-time configuration option on Linux (though not
on Windows); added with much help from Thomas Wouters.
- Integration into the CPython build system is obviously different from
building a standalone zoneinfo module wheel.
- This includes configuration to install the tzdata package as part of
CI, though only on the coverage jobs. Introducing a PyPI dependency as
part of the CI build was controversial, and this is seen as less of a
major change, since the coverage jobs already depend on pip and PyPI.
Additional changes that were introduced as part of this PR, most / all of
which were backported to the reference implementation:
- Fixed reference and memory leaks
With much debugging help from Pablo Galindo
- Added smoke tests ensuring that the C and Python modules are built
The import machinery can be somewhat fragile, and the "seamlessly falls
back to pure Python" nature of this module makes it so that a problem
building the C extension or a failure to import the pure Python version
might easily go unnoticed.
- Adjustments to zoneinfo.__dir__
Suggested by Petr Viktorin.
- Slight refactorings as suggested by Steve Dower.
- Removed unnecessary if check on std_abbr
Discovered this because of a missing line in branch coverage.
Rather than using Burn "Persisted" variables we now add registry keys for each added feature. These can be detected by the installer regardless of which version installed them, and we use this for Modify and Upgrade. In particular, Upgrades can't access the Persisted variables, but can find well-known registry keys.
There are also some changes to the bootstrap app to properly handle upgrades.
Finally, a few minor improvements to the Windows build to keep things tidier.
CoderTCY