Glom

_(December 25, 2018)_

A couple features related to
[`assign()`](https://glom.readthedocs.io/en/latest/mutation.html#glom.assign)
and other minor additions and fixes.

- Add new `missing` parameter to `assign()`, to autogenerate new
datastructures at paths that don't exist. Read more at the bottom of
the [`Assign` spec docstring](https://glom.readthedocs.io/en/latest/mutation.html#glom.Assign).
- Allow `Assign` to operate on `S`-based specs to assign to the spec.
- Add the [`STOP` singleton](https://glom.readthedocs.io/en/latest/api.html#glom.STOP).
`STOP` is to [`SKIP`](https://glom.readthedocs.io/en/latest/api.html#glom.SKIP)
what `break` is to `continue`. Useful as a default with conditional specs like
[`Check()`](https://glom.readthedocs.io/en/latest/matching.html#validation-with-check).

18.3.1

---

_(August 22, 2018)_

Fix a small bug where `Assign()` raised a `TypeError` instead of a
`GlomError` subtype. This release added
[`PathAssignError`](https://glom.readthedocs.io/en/latest/api.html#glom.PathAssignError),
which is now raised instead.

_(August 14, 2018)_

This release introduces the `Assign` Spec type, and its accompanying
`glom.assign()` "deep-set" convenience function, a feature that
required the refinement of glom's Extension API. `Path` and `T` also
saw improvements.

- `Assign` Spec type and `glom.assign()` top-level function for deep setting.
- Extensions (and advanced users) can now register new operations. For
instance, `Assign` registers `"assign"`, which is now a peer of
`"get"` and `"iterate"`, which were the only built-in operations
glom provided.
- Extensions no longer need to be registered. A `glom` extension is an
instance of any type that provides a `glomit()` method. Full docs
coming soon.
- `T` and other `TType` instances now pickle correctly, fixing [48][i48]
- `Path` instances now behave like strings, with indexing returning
new `Path` objects, with full slice syntax support.
- `Path` also supports `.values()` and `.items()` methods, which
enable getting sequences of the data backing the `Path()`, for when
a sub-`Path` object is not desirable.
- `Path` objects are now comparable for equality. To compare a `T`,
simply wrap it in a `Path()` use the `==` operator.

[i48]: https://github.com/mahmoud/glom/issues/48

_(July 5, 2018)_

This sizable release incorporates a lot of the post-announcement
feedback. Several advanced features were added, including an extension
API and "Scope" support. While this involved a large refactor, all
external APIs are 100% backwards-compatible.

In other good news, coverage is up over 90% and on track to go even
higher. Check out all the well-tested enhancements below!

- Introduce the `glom`'s first-class Extension system. Docs are a work
in progress, but given that all the internals are implemented in
terms of the system, don't hesitate to look under the hood and start
experimenting. Addresses [9][i9].
- The Extension system involved a runtime refactor to add a concept of
"scope" to `glom`. Until now, glom has only supported operating on a
single "target", making it the only object in scope. Now, it's also
possible to add other objects to the scope, making multi-target
glomming a reality for advanced users.
- Add initial version of `Check()`, a specifier type aimed at
providing target validation while glomming. Addresses [7][i7].
- Make `Spec` work for object-oriented glom use. Usage is similar to
Python's `re.compile`: predefine a `Spec` object, call
`spec.glom(target)` later. Addresses [14][i14]
- Add YAML support to CLI. PyYAML was added as an "extras" dependency
and is not installed by default. glom will pick up any existing
installed yaml library and use that, or you can `pip install
glom[yaml]` to explicitly install support. See [26][i26] for
details. Thanks dfezzie!
- Made `T` and `Path` share evaluation, repr, and exception paths, closing [6][i6]
- add `default_factory` argument to Coalesce, with semantics identical
to Python's built-in defaultdict.

[i6]: https://github.com/mahmoud/glom/issues/6
[i7]: https://github.com/mahmoud/glom/issues/7
[i9]: https://github.com/mahmoud/glom/issues/9
[i14]: https://github.com/mahmoud/glom/issues/14
[i26]: https://github.com/mahmoud/glom/issues/26

_(May 9, 2018)_

Initial release.

See the [announcement post][initial_announce] for an idea of the
functionality available.

This release itself added the console interface (CLI).

_(May 6, 2018)_

Still in semi-public beta. This release added `T` objects and better
error messages.

_(April 30, 2018)_

Semi-public beta release. Most of the functionality glom had on
[announcement][initial_announce].

[initial_announce]: https://sedimental.org/glom_restructured_data.html