What's New in Pylint 2.1

Release

2.1

Date

2018-08-01

Summary -- Release highlights

  • This release mostly includes fixes for bugs found after the launch of 2.0.

New checkers

  • A new check was added, misplaced-format-function.

    This message is emitted when pylint detects that a format function is called on non str object. This can occur due to wrong placement of closing bracket, e.g

    print('value: {}').format(123) # bad

print('value: {}'.format(123)) # good

Other Changes

  • try-except-raise check was demoted from an error to a warning, as part of issue #2323.

  • Correctly handle the new name of the Python implementation of the abc module.

    In Python 3.7, the abc module has both a C implementation as well as a Python one, but the Python implementation has a different file name that what pylint was expecting, resulting in some checks getting confused.

  • Modules with __getattr__ are exempted by default from no-member

    There's no easy way to figure out if a module has a particular member when the said module uses __getattr__, which is a new addition to Python 3.7. Instead we assume the safe thing to do, in the same way we do for classes, and skip those modules from checking.

  • invalid name is no longer triggered for function and attribute names longer than 30 characters. The upper limit was removed completely.

  • Fix false-positive undefined-variable for self referential class name in lamdbas

  • no-else-return also specifies the type of the branch that is causing the error.

  • Fixed inconsistent behaviour for bad-continuation on first line of file.

  • Fixed a bug where pylint was not able to disable certain messages on the last line through the global disable option.

  • pylint no longer emits useless-return when it finds a single statement that is the return itself

    We still want to be explicit when a function is supposed to return an optional value; even though pass could still work, it's not explicit enough and the function might look like it's missing an implementation.

  • Fixed a bug where pylint was crashing when being unable to infer the value of an argument to next()

  • pylint no longer emit not-an-iterable when dealing with async iterators.

  • pylint gained the ability to specify a default docstring type for when the check cannot guess the type

    For this we added a --default-docstring-type command line option.