What's New in Pyramid 1.8¶
This article explains the new features in Pyramid version 1.8 as compared to its predecessor, Pyramid 1.7. It also documents backwards incompatibilities between the two versions and deprecations added to Pyramid 1.8, as well as software dependency changes and notable documentation additions.
Major Feature Additions¶
pyramid.view.exception_view_config()decorator. It is now possible using these methods or via the new
pyramid.config.Configurator.add_view()to add a view which will only be matched when handling an exception. Previously, any exception views were also registered for a traversal context that inherited from the exception class which prevented any exception-only optimizations. See https://github.com/Pylons/pyramid/pull/2660
pserve --reloadnow uses the hupper library to monitor file changes. This comes with many improvements:
If the watchdog package is installed then monitoring will be done using inotify instead of cpu and disk-intensive polling.
The monitor is now a separate process that will not crash and starts up before any of your code.
The monitor will not restart the process after a crash until a file is saved.
The monitor works on windows.
You can now trigger a reload manually from a pyramid view or any other code via
hupper.get_reloader().trigger_reload(). Kind of neat.
You can trigger a reload by issuing a
SIGHUPto the monitor process.
Minor Feature Additions¶
Python 3.6 compatibility. https://github.com/Pylons/pyramid/issues/2835
_get_credentialsprivate method of
pyramid.authentication.BasicAuthAuthenticationPolicyhas been extracted into standalone function
pyramid.authentication.extract_http_basic_credentials(), this function extracts HTTP Basic credentials from a
requestobject, and returns them as a named tuple. See https://github.com/Pylons/pyramid/pull/2662
Pyramid 1.4 silently dropped a feature of the configurator that has been restored. It's again possible for action discriminators to conflict across different action orders. See https://github.com/Pylons/pyramid/pull/2757
pyramid.paster.bootstrap()and its sibling
pyramid.scripting.prepare()can now be used as context managers to automatically invoke the
closerand pop threadlocals off of the stack to prevent memory leaks. See https://github.com/Pylons/pyramid/pull/2760
pyramid.interfaces.IViewDeriverInfowhich can be used by view derivers to determine if they are wrapping a view which only handles exceptions. This means that it is no longer necessary to perform request-time checks for
request.exceptionto determine if the view is handling an exception - the pipeline can be optimized at config-time. See https://github.com/Pylons/pyramid/pull/2660
--package-nameto allow you to create a new project in an existing folder with a different package name than the project name. See https://github.com/Pylons/pyramid/pull/2783
pserveshould now work with
geventand other workers that need to monkeypatch the process, assuming the server and / or the app do so as soon as possible before importing the rest of pyramid. See https://github.com/Pylons/pyramid/pull/2797
Pyramid no longer copies the settings object passed to the
pyramid.config.Configurator(settings=). The original
dictis kept. See https://github.com/Pylons/pyramid/pull/2823
The csrf trusted origins setting may now be a whitespace-separated list of domains. Previously only a python list was allowed. Also, it can now be set using the
PYRAMID_CSRF_TRUSTED_ORIGINSenvironment variable similar to other settings. See https://github.com/Pylons/pyramid/pull/2823
[pserve]section is supported in your config files with a
watch_fileskey that can configure
pserve --reloadto monitor custom file paths. See https://github.com/Pylons/pyramid/pull/2827
Allow streaming responses to be made from subclasses of
pyramid.httpexceptions.HTTPException. Previously the response would be unrolled while testing for a body, making it impossible to stream a response. See https://github.com/Pylons/pyramid/pull/2863
Update starter, alchemy and zodb scaffolds to support IPv6 by using the new
listendirectives in waitress. See https://github.com/Pylons/pyramid/pull/2853
All p* scripts now use argparse instead of optparse. This improves their
--helpoutput as well as enabling nicer documentation of their options. See https://github.com/Pylons/pyramid/pull/2864
pyramid.config.Configurator.add_translation_dirs()to allow later calls to place translation directories at a higher priority then earlier calls. See https://github.com/Pylons/pyramid/pull/2902
Added a new
pyramid.config.Configurator.set_default_csrf_options`()which can be used to determine per-request whether CSRF checking should be enabled to allow for a mix authentication methods. Only cookie-based methods generally require CSRF checking. See https://github.com/Pylons/pyramid/pull/2778
Following the Pyramid deprecation period (1.6 -> 1.8), daemon support for pserve has been removed. This includes removing the daemon commands (start, stop, restart, status) as well as the following arguments:
To run your server as a daemon you should use a process manager instead of pserve.
Change static view to avoid setting the
Content-Encodingresponse header to an encoding guessed using Python's
mimetypesmodule. This was causing clients to decode the content of gzipped files when downloading them. The client would end up with a
foo.txt.gzfile on disk that was already decoded, thus should really be
foo.txt. Also, the
Content-Encodingshould only have been used if the client itself broadcast support for the encoding via
Accept-Encodingrequest headers. See https://github.com/Pylons/pyramid/pull/2810
pcreateis now interactive by default. You will be prompted if a file already exists with different content. Previously if there were similar files it would silently skip them unless you specified
--overwrite. See https://github.com/Pylons/pyramid/pull/2775
Support for the
IContextURLinterface that was deprecated in Pyramid 1.3 has been removed. See https://github.com/Pylons/pyramid/pull/2822
Settings are no longer accessible as attributes on the settings object (e.g.
request.registry.settings.foo). This was deprecated in Pyramid 1.2. See https://github.com/Pylons/pyramid/pull/2823
Removed undocumented argument
pyramid.static.static_view. This argument was shipped accidentally in Pyramid 1.6. See https://github.com/Pylons/pyramid/pull/2681
pcreatescript and the core scaffolds (
zodb) have been deprecated.
They have been replaced with the decision to embrace the popular cookiecutter project as a best-of-breed project templating solution.
pcreatewas originally introduced when very few alternatives existed that supported Python 3. Fortunately the situation has improved and with possible tooling support for cookiecutters being discussed by major IDEs, and the simplicity of the jinja2 syntax, it is exciting to embrace the project moving forward!
All of Pyramid's official scaffolds as well as the tutorials have been ported to cookiecutters:
Update Typographical Conventions. https://github.com/Pylons/pyramid/pull/2838
Update HACKING.txt from stale branch that was never merged to master. See https://github.com/Pylons/pyramid/pull/2782
Updated Windows installation instructions and related bits. See https://github.com/Pylons/pyramid/issues/2661
Fix an inconsistency in the documentation between view predicates and route predicates and highlight the differences in their APIs. See https://github.com/Pylons/pyramid/pull/2764
Clarify a possible misuse of the
headerskwarg to subclasses of
pyramid.httpexceptions.HTTPExceptionin which more appropriate kwargs from the parent class
pyramid.response.Responseshould be used instead. See https://github.com/Pylons/pyramid/pull/2750
The SQLAlchemy + URL Dispatch + Jinja2 (
wiki2) and ZODB + Traversal + Chameleon (
wiki) tutorials have been updated to utilize the new cookiecutters and drop support for the
Quick Tour, Quick Tutorial, and most files throughout the documentation have been updated to use cookiecutters instead of pcreate and scaffolds. See https://github.com/Pylons/pyramid/pull/2888 and https://github.com/Pylons/pyramid/pull/2889
mod_wsgitutorial to use cookiecutters and Apache 2.4+. See https://github.com/Pylons/pyramid/pull/2901