Full changelog

What's New in Pylint 2.0?

Release date: 2018-07-15

• try-except-raise should not be emitted if there are any parent exception class handlers.

  Closes #2284

• trailing-comma-tuple can be emitted for return statements as well.

  Closes #2269

• Fix a false positive inconsistent-return-statements message when exception is raised inside an else statement.

  Closes #1782

• ImportFrom nodes correctly use the full name for the import sorting checks.

  Closes #2181

• [].extend and similar builtin operations don't emit dict-*-not-iterating with the Python 3 porting checker

  Closes #2187

• Add a check consider-using-dict-comprehension which is emitted if for dict initialization the old style with list comprehensions is used.

• Add a check consider-using-set-comprehension which is emitted if for set initialization the old style with list comprehensions is used.

• logging-not-lazy is emitted whenever pylint infers that a string is built with addition

  Closes #2193

• Add a check chained-comparison which is emitted if a boolean operation can be simplified by chaining some of its operations. e.g "a < b and b < c", can be simplified as "a < b < c".

  Closes #2032

• Add a check consider-using-in for comparisons of a variable against multiple values with "==" and "or"s instead of checking if the variable is contained "in" a tuple of those values.

• in is considered iterating context for some of the Python 3 porting checkers

  Closes #2186

• Add --ignore-none flag to control if pylint should warn about no-member where the owner is None

• Fix a false positive related to too-many-arguments and bounded __get__ methods

  Closes #2172

• mcs as the first parameter of metaclass's __new__ method was replaced by cls

  Closes #2028

• assignment-from-no-return considers methods as well.

  Closes #2081

• Support typing.TYPE_CHECKING for unused-import errors

  Closes #1948

• Inferred classes at a function level no longer emit invalid-name when they don't respect the variable regular expression

  Closes #1049

• Added basic support for postponed evaluation of function annotations.

  Closes #2069

• Fix a bug with missing-kwoa and variadics parameters

  Closes #1111

• simplifiable-if-statement takes in account only when assigning to same targets

  Closes #1984

• Make len-as-condition test more cases, such as len() < 1 or len <= 0

• Fix false-positive line-too-long message emission for commented line at the end of a module

  Closes #1950

• Fix false-positive bad-continuation for with statements

  Closes #461

• Don't warn about stop-iteration-return when using next() over itertools.count

  Closes #2158

• Add a check consider-using-get for unidiomatic usage of value/default-retrieval for a key from a dictionary

  Closes #2076

• invalid-slice-index is not emitted when the slice is used as index for a complex object.

  We only use a handful of known objects (list, set and friends) to figure out if we should emit invalid-slice-index when the slice is used to subscript an object.

• Don't emit unused-import anymore for typing imports used in type comments.

• Add a new check 'useless-import-alias'.

  Closes #2052

• Add comparison-with-callable to warn for comparison with bare callable, without calling it.

  Closes #2082

• Don't warn for missing-type-doc and/or missing-return-type-doc, if type annotations exist on the function signature for a parameter and/or return type.

  Closes #2083

• Add --exit-zero option for continuous integration scripts to more easily call Pylint in environments that abort when a program returns a non-zero (error) status code.

  Closes #2042

• Warn if the first argument of an instance/ class method gets assigned

  Closes #977

• New check comparison-with-itself to check comparison between same value.

  Closes #2051

• Add a new warning, 'logging-fstring-interpolation', emitted when f-string is used within logging function calls.

  Closes #1998

• Don't show 'useless-super-delegation' if the subclass method has different type annotations.

  Closes #1923

• Add unhashable-dict-key check.

  Closes #586

• Don't warn that a global variable is unused if it is defined by an import

  Closes #1453

• Skip wildcard import check for __init__.py.

  Closes #2026

• The Python 3 porting mode can now run with Python 3 as well.

• too-few-public-methods is not emitted for dataclasses.

  Closes #1793

• New verbose mode option, enabled with --verbose command line flag, to display of extra non-checker-related output. It is disabled by default.

  Closes #1863

• undefined-loop-variable takes in consideration non-empty iterred objects before emitting

  Closes #2039

• Add support for numpydoc optional return value names.

  Closes #2030

• singleton-comparison accounts for negative checks

  Closes #2037

• Add a check consider-using-in for comparisons of a variable against multiple values with "==" and "or"s instead of checking if the variable is contained "in" a tuple of those values.

  Closes #1977

• defaultdict and subclasses of dict are now handled for dict-iter-* checks

  Closes #2005

• logging-format-interpolation also emits when f-strings are used instead of % syntax.

  Closes #1788

• Don't trigger misplaced-bare-raise when the raise is in a finally clause

  Closes #1924

• Add a new check, possibly-unused-variable.

  This is similar to unused-variable, the only difference is that it is emitted when we detect a locals() call in the scope of the unused variable. The locals() call could potentially use the said variable, by consuming all values that are present up to the point of the call. This new check allows to disable this error when the user intentionally uses locals() to consume everything.

  Closes #1909.

• no-else-return accounts for multiple cases

  The check was a bit overrestrictive because we were checking for return nodes in the .orelse node. At that point though the if statement can be refactored to not have the orelse. This improves the detection of other cases, for instance it now detects TryExcept nodes that are part of the .else branch.

  Closes #1852

• Added two new checks, invalid-envvar-value and invalid-envvar-default.

  The former is trigger whenever pylint detects that environment variable manipulation functions uses a different type than strings, while the latter is emitted whenever the said functions are using a default variable of different type than expected.

• Add a check consider-using-join for concatenation of strings using str.join(sequence)

  Closes #1952

• Add a check consider-swap-variables for swapping variables with tuple unpacking

  Closes #1922

• Add new checker try-except-raise that warns the user if an except handler block has a raise statement as its first operator. The warning is shown when there is a bare raise statement, effectively re-raising the exception that was caught or the type of the exception being raised is the same as the one being handled.

• Don't crash on invalid strings when checking for logging-format-interpolation

  Closes #1944

• Exempt __doc__ from triggering a redefined-builtin

  __doc__ can be used to specify a docstring for a module without passing it as a first-statement string.

• Fix false positive bad-whitespace from function arguments with default values and annotations

  Closes #1831

• Fix stop-iteration-return false positive when next builtin has a default value in a generator

  Closes #1830

• Fix emission of false positive no-member message for class with "private" attributes whose name is mangled.

  Closes #1643

• Fixed a crash which occurred when Uninferable wasn't properly handled in stop-iteration-return

  Closes #1779

• Use the proper node to get the name for redefined functions (#1792)

  Closes #1774

• Don't crash when encountering bare raises while checking inconsistent returns

  Closes #1773

• Fix a false positive inconsistent-return-statements message when if statement is inside try/except.

  Closes #1770

• Fix a false positive inconsistent-return-statements message when while loop are used.

  Closes #1772

• Correct column number for whitespace conventions.

  Previously the column was stuck at 0

  Closes #1649

• Fix unused-argument false positives with overshadowed variable in dictionary comprehension.

  Closes #1731

• Fix false positive inconsistent-return-statements message when never returning functions are used (i.e sys.exit for example).

  Closes #1771

• Fix error when checking if function is exception, as in bad-exception-context.

• Fix false positive inconsistent-return-statements message when a function is defined under an if statement.

  Closes #1794

• New useless-return message when function or method ends with a "return" or "return None" statement and this is the only return statement in the body.

• Fix false positive inconsistent-return-statements message by avoiding useless exception inference if the exception is not handled.

  Closes #1794 (second part)

• Fix bad thread instantiation check when target function is provided in args.

  Closes #1840

• Fixed false positive when a numpy Attributes section follows a Parameters section

  Closes #1867

• Fix incorrect file path when file absolute path contains multiple path_strip_prefix strings.

  Closes #1120

• Fix false positive undefined-variable for lambda argument in class definitions

  Closes #1824

• Add of a new checker that warns the user if some messages are enabled or disabled by id instead of symbol.

  Closes #1599

• Suppress false-positive not-callable messages from certain staticmethod descriptors

  Closes #1699

• Fix indentation handling with tabs

  Closes #1148

• Fix false-positive bad-continuation error

  Closes #638

• Fix false positive unused-variable in lambda default arguments

  Closes #1921 Closes #1552 Closes #1099 Closes #210

• Updated the default report format to include paths that can be clicked on in some terminals (e.g. iTerm).

• Fix inline def behavior with too-many-statements checker

  Closes #1978

• Fix KeyError raised when using docparams and NotImplementedError is documented.

  Closes #2102

• Fix 'method-hidden' raised when assigning to a property or data descriptor.

• Fix emitting useless-super-delegation when changing the default value of keyword arguments.

  Closes #2022

• Expand ignored-argument-names include starred arguments and keyword arguments

  Closes #2214

• Fix false-positive undefined-variable in nested lambda

  Closes #760

• Fix false-positive bad-whitespace message for typing annoatations with ellipses in them

  Close 1992

• Broke down "missing-docstrings" between "module", "class" and "function"

  For this to work we had to make multiple messages with the same old name possible.

  Closes #1164