[code-quality] Pylint 1.5.0 / Astroid 1.4.1 released

[Claudiu Popa]

Hello,


I'm happy to announce you the release of Pylint 1.5.0,
respectively Astroid 1.4.1.

It's been over a year since the last major release
and the amount of changes that were brought into pylint
in this time is humongous, with over 30 new checks
and tons of bug fixes.

I would like to use this occasion for thanking for their contributions
the new committers who joined pylint's team in the past months,
ceridwen and Dmitry, as well as thanking the
contributors that made this release possible.

Here are some of the major changes of this release:

- We finally support Python 3.5 in both projects.

- We stopped depending on logilab-common, which
  means that users of the popular testing framework
  pytest will finally stop being confused by having
  two executables with the same name doing different
  things.

- Almost 30 new checks you might enjoy not having in
  your project. These checks fall into multiple categories,
  regarding maintainability, readability, recommendations
  for improving the code, as well as new type-checking
  capabilities. They are:

    'wrong-import-order', 'ungrouped-imports', 'wrong-import-position',
    'unneeded-not', 'simplifiable-if-condition', 'too-many-boolean-expressions'
    'too-many-nested-blocks', 'multiple-imports', 'duplicate-except',
    'using-constant-test', 'confusing-with-statement', 'singleton-comparison',
    'misplaced-comparison-constant', 'consider-using-enumerate',
    'nonlocal-and-global', 'continue-in-finally', 'misplaced-bare-raise',
    'nonlocal-without-binding', 'yield-inside-async-function',
    'too-many-star-expressions', 'invalid-star-assignment-target',
    'import-star-module-level, 'star-needs-assignment',
    'unexpected-special-method-signature', 'repeated-keyword'.

    Some new type checks for finding violations of the type system
    are 'unsubscriptable-object', 'unsupported-membership-test',
    'not-an-iterable', 'not-context-manager', 'not-async-context-manager',
    'duplicate-bases' and 'inconsistent-mro'.


- We also added a new 'extensions' component, which contains optional
  checkers that needs to be activated explicitly.

  These includes 'extensions.check_docs', which verifies a bunch of
  properties of the docstrings, such as checking that all function,
  method and constructor parameters are mentioned
  in the params and types part of the docstring. Also, it checks that
  there are no naming inconsistencies between the signature and
  the documentation, i.e. also report documented parameters that are missing
  in the signature. This is important to find cases where parameters are
  renamed only in the code, not in the documentation.

  Activate this checker with:

      --load-plugins=pylint.extensions.check_docs

Most of the work was put into astroid though, which got more capable in this
period of time. Unfortunately, more than half of the work that went into it was
postponed for astroid 1.6 and astroid 2.0, since it wasn't deemed stable
enough for this release.
New features worth mentioning are:

  - Python 3.5 support

  - some of the nodes were renamed in order to be more similar to
    builtin's ast module, such as Class to ClassDef, Function to
    FunctionDef Getattr to Attribute etc, the old names being slated
    for removal in astroid 2.0.
    This affects the plugins as well, since it means that the visit
    methods should use the new names instead (so visit_classdef for class).
    Old names are still supported in visit methods for a while, until
    pylint 2.0. Activating the warnings when running should result in
    spurious PendingDeprecationWarnings when using the old node names.

  - add proper grammatical names for `infered` and `ass_type` methods,
    namely `inferred` and `assign_type`.

    The old methods will raise PendingDeprecationWarning, being slated
    for removal in astroid 2.0.

  - we added a new convenience API, `astroid.parse`, which can be used
    to retrieve an astroid AST from a source code string, similar to how
    ast.parse can be used to obtain a Python AST from a source string.

  - There's a new separate step for transforms.

    Until now, the transforms were applied at the same time the tree was
    being built. This was problematic if the transform functions were
    using inference, since the inference was executed on a partially
    constructed tree, which led to failures when post-building
    information was needed.

  - Better support for understanding builtins.

    We're understanding a bunch of new builtins, but unfortunately
    most of them weren't released, since they weren't stable
    enough for now, due to some inherent problems that astroid
    has. The most important that's released though is the understanding
    of super, which means that we can now detect problems of sort:

    class A(B, C, D):
      def __init__(self):
          super(A, self).call_missing_method()

You can read the complete changelog here
https://bitbucket.org/logilab/astroid/raw/4f45b6fc4c23b80b4f7154add1b9d9cee3a54297/ChangeLog
and https://bitbucket.org/logilab/pylint/raw/2871c4d7084478b5db02f384e4e5167641c698f2/ChangeLog

Now with every release there's going to be new false positives or regressions
or things that could be improved. Don't hesitate to open an issue or to
send a PR if you notice something's amiss and we'll try to have new
bug fix releases as soon as possible (you might have noticed that's
astroid 1.4.1..)

As a final note, we're planning to switch to GitHub soon, which will mean an
improved CI for us, resulting in less maintenance pain.


Thank you for reading all this and enjoy pylinting!


Claudiu