Remove a couple of Python 2 specific checks

The Removed Python 2 specific checks are: deprecated-lambda, nonstandard-exception,
lowercase-l-suffix, slots-on-old-class, super-on-old-class, property-on-old-class,
old-style-class.

Close #1896

CONTRIBUTORS.txt

@@ -217,3 +217,5 @@ contributors:
 * Carey Metcalfe: demoted `try-except-raise` from error to warning
 
 * Marcus Näslund (naslundx): contributor 
+
+* Natalie Serebryakova: contributor

README.rst

@@ -79,5 +79,3 @@ Pylint is shipped with following additional commands:
 * pyreverse: an UML diagram generator
 * symilar: an independent similarities checker
 * epylint: Emacs and Flymake compatible Pylint
-
-

pylint/checkers/base.py

@@ -1725,37 +1725,6 @@ def visit_pass(self, node):
                  (node.parent.doc is not None))):
             self.add_message('unnecessary-pass', node=node)
 
-
-class LambdaForComprehensionChecker(_BasicChecker):
-    """check for using a lambda where a comprehension would do.
-
-    See <http://www.artima.com/weblogs/viewpost.jsp?thread=98196>
-    where GvR says comprehensions would be clearer.
-    """
-
-    msgs = {'W0110': ('map/filter on lambda could be replaced by comprehension',
-                      'deprecated-lambda',
-                      'Used when a lambda is the first argument to "map" or '
-                      '"filter". It could be clearer as a list '
-                      'comprehension or generator expression.',
-                      {'maxversion': (3, 0)}),
-           }
-
-    @utils.check_messages('deprecated-lambda')
-    def visit_call(self, node):
-        """visit a Call node, check if map or filter are called with a
-        lambda
-        """
-        if not node.args:
-            return
-        if not isinstance(node.args[0], astroid.Lambda):
-            return
-        infered = utils.safe_infer(node.func)
-        if (utils.is_builtin_object(infered)
-                and infered.name in ['map', 'filter']):
-            self.add_message('deprecated-lambda', node=node)
-
-
 def _is_one_arg_pos_call(call):
     """Is this a call with exactly 1 argument,
     where that argument is positional?
@@ -1954,5 +1923,4 @@ def register(linter):
     linter.register_checker(NameChecker(linter))
     linter.register_checker(DocStringChecker(linter))
     linter.register_checker(PassChecker(linter))
-    linter.register_checker(LambdaForComprehensionChecker(linter))
     linter.register_checker(ComparisonChecker(linter))

pylint/checkers/exceptions.py

@@ -118,11 +118,6 @@ def _annotated_unpack_infer(stmt, context=None):
               'operator. This is useless because it raises back the exception '
               'immediately. Remove the raise operator or the entire '
               'try-except-raise block!'),
-    'W0710': ('Exception doesn\'t inherit from standard "Exception" class',
-              'nonstandard-exception',
-              'Used when a custom exception class is raised but doesn\'t '
-              'inherit from the builtin "Exception" class.',
-              {'maxversion': (3, 0)}),
     'W0711': ('Exception to catch is the result of a binary "%s" operation',
               'binary-op-exception',
               'Used when the exception to catch is of the form '

pylint/checkers/format.py

@@ -91,7 +91,7 @@
     'C0302': ('Too many lines in module (%s/%s)',  # was W0302
               'too-many-lines',
               'Used when a module has too many lines, reducing its readability.'
-             ),
+              ),
     'C0303': ('Trailing whitespace',
               'trailing-whitespace',
               'Used when there is whitespace between the end of a line and the '
@@ -131,12 +131,6 @@
               {'old_names': [('C0323', 'no-space-after-operator'),
                              ('C0324', 'no-space-after-comma'),
                              ('C0322', 'no-space-before-operator')]}),
-    'W0332': ('Use of "l" as long integer identifier',
-              'lowercase-l-suffix',
-              'Used when a lower case "l" is used to mark a long integer. You '
-              'should use an upper case "L" since the letter "l" looks too much '
-              'like the digit "1"',
-              {'maxversion': (3, 0)}),
     'C0327': ('Mixed line endings LF and CRLF',
               'mixed-line-endings',
               'Used when there are mixed (LF and CRLF) newline signs in a file.'),
@@ -547,7 +541,7 @@ class FormatChecker(BaseTokenChecker):
                  'choices': ['', 'LF', 'CRLF'],
                  'help': ('Expected format of line ending, '
                           'e.g. empty (any line ending), LF or CRLF.')}),
-              )
+               )
 
     def __init__(self, linter=None):
         BaseTokenChecker.__init__(self, linter)
@@ -906,7 +900,7 @@ def process_tokens(self, tokens):
             else:
                 handler(tokens, idx)
 
-        line_num -= 1 # to be ok with "wc -l"
+        line_num -= 1  # to be ok with "wc -l"
         if line_num > self.config.max_module_lines:
             # Get the line where the too-many-lines (or its message id)
             # was disabled or default to 1.
@@ -997,7 +991,7 @@ def visit_default(self, node):
         if not node.is_statement:
             return
         if not node.root().pure_python:
-            return # XXX block visit of child nodes
+            return  # XXX block visit of child nodes
         prev_sibl = node.previous_sibling()
         if prev_sibl is not None:
             prev_line = prev_sibl.fromlineno
@@ -1118,7 +1112,7 @@ def check_indent_level(self, string, expected, line_num):
         """return the indent level of the string
         """
         indent = self.config.indent_string
-        if indent == '\\t': # \t is not interpreted in the configuration file
+        if indent == '\\t':  # \t is not interpreted in the configuration file
             indent = '\t'
         level = 0
         unit_size = len(indent)

pylint/checkers/imports.py

@@ -123,6 +123,7 @@ def _ignore_import_failure(node, modname, ignored_modules):
 
 # utilities to represents import dependencies as tree and dot graph ###########
 
+
 def _make_tree_defs(mod_files_list):
     """get a list of 2-uple (module, list_of_files_which_import_this_module),
     it will return a dictionary to represent this as a tree
@@ -303,31 +304,32 @@ class ImportsChecker(BaseChecker):
                 {'default': DEFAULT_STANDARD_LIBRARY,
                  'type': 'csv',
                  'metavar': '<modules>',
-                 'help': 'Force import order to recognize a module as part of'
-                         ' the standard compatibility libraries.'}
-               ),
+                 'help': 'Force import order to recognize a module as part of '
+                         'the standard compatibility libraries.'}
+                ),
                ('known-third-party',
                 {'default': DEFAULT_KNOWN_THIRD_PARTY,
                  'type': 'csv',
                  'metavar': '<modules>',
-                 'help': 'Force import order to recognize a module as part of'
-                         ' a third party library.'}
-               ),
+                 'help': 'Force import order to recognize a module as part of '
+                         'a third party library.'}
+                ),
                ('analyse-fallback-blocks',
                 {'default': False,
                  'type': 'yn',
                  'metavar': '<y_or_n>',
                  'help': 'Analyse import fallback blocks. This can be used to '
-                         'support both Python 2 and 3 compatible code, which means that '
-                         'the block might have code that exists only in one or another '
-                         'interpreter, leading to false positives when analysed.'},
-               ),
+                         'support both Python 2 and 3 compatible code, which '
+                         'means that the block might have code that exists '
+                         'only in one or another interpreter, leading to false '
+                         'positives when analysed.'},
+                ),
                ('allow-wildcard-with-all',
                 {'default': False,
                  'type': 'yn',
                  'metavar': '<y_or_n>',
                  'help': 'Allow wildcard imports from modules that define __all__.'}),
-              )
+               )
 
     def __init__(self, linter=None):
         BaseChecker.__init__(self, linter)
@@ -340,7 +342,7 @@ def __init__(self, linter=None):
                          self._report_external_dependencies),
                         ('RP0402', 'Modules dependencies graph',
                          self._report_dependencies_graph),
-                       )
+                        )
 
         self._site_packages = self._compute_site_packages()
 
@@ -586,7 +588,7 @@ def _check_imports_order(self, _module_node):
         std_imports = []
         third_party_imports = []
         first_party_imports = []
-        # need of a list that holds third or first party ordered import
+        # need of a list that holds third or first party ordered import
         external_imports = []
         local_imports = []
         third_party_not_ignored = []
@@ -671,9 +673,9 @@ def _check_relative_import(self, modnode, importnode, importedmodnode,
         if not self.linter.is_message_enabled('relative-import'):
             return None
         if importedmodnode.file is None:
-            return False # built-in module
+            return False  # built-in module
         if modnode is importedmodnode:
-            return False # module importing itself
+            return False  # module importing itself
         if modnode.absolute_import_activated() or getattr(importnode, 'level', None):
             return False
         if importedmodnode.name != importedasname:

pylint/checkers/newstyle.py

@@ -17,7 +17,7 @@
 
 import astroid
 
-from pylint.interfaces import IAstroidChecker, INFERENCE, INFERENCE_FAILURE, HIGH
+from pylint.interfaces import IAstroidChecker
 from pylint.checkers import BaseChecker
 from pylint.checkers.utils import (
     check_messages,
@@ -26,14 +26,6 @@
 )
 
 MSGS = {
-    'E1001': ('Use of __slots__ on an old style class',
-              'slots-on-old-class',
-              'Used when an old style class uses the __slots__ attribute.',
-              {'maxversion': (3, 0)}),
-    'E1002': ('Use of super on an old style class',
-              'super-on-old-class',
-              'Used when an old style class uses the super builtin.',
-              {'maxversion': (3, 0)}),
     'E1003': ('Bad first argument %r given to super()',
               'bad-super-call',
               'Used when another argument than the current class is given as '
@@ -43,17 +35,6 @@
               'Used when the super builtin didn\'t receive an '
               'argument.',
               {'maxversion': (3, 0)}),
-    'W1001': ('Use of "property" on an old style class',
-              'property-on-old-class',
-              'Used when Pylint detect the use of the builtin "property" '
-              'on an old style class while this is relying on new style '
-              'classes features.',
-              {'maxversion': (3, 0)}),
-    'C1001': ('Old-style class defined.',
-              'old-style-class',
-              'Used when a class is defined that does not inherit from another '
-              'class and does not inherit explicitly from "object".',
-              {'maxversion': (3, 0)})
     }
 
 
@@ -74,39 +55,7 @@ class NewStyleConflictChecker(BaseChecker):
     # configuration options
     options = ()
 
-    @check_messages('slots-on-old-class', 'old-style-class')
-    def visit_classdef(self, node):
-        """ Check __slots__ in old style classes and old
-        style class definition.
-        """
-        if '__slots__' in node and not node.newstyle:
-            confidence = (INFERENCE if has_known_bases(node)
-                          else INFERENCE_FAILURE)
-            self.add_message('slots-on-old-class', node=node,
-                             confidence=confidence)
-        # The node type could be class, exception, metaclass, or
-        # interface.  Presumably, the non-class-type nodes would always
-        # have an explicit base class anyway.
-        if not node.bases and node.type == 'class' and not node.metaclass():
-            # We use confidence HIGH here because this message should only ever
-            # be emitted for classes at the root of the inheritance hierarchyself.
-            self.add_message('old-style-class', node=node, confidence=HIGH)
-
-    @check_messages('property-on-old-class')
-    def visit_call(self, node):
-        """check property usage"""
-        parent = node.parent.frame()
-        if (isinstance(parent, astroid.ClassDef) and
-                not parent.newstyle and
-                isinstance(node.func, astroid.Name)):
-            confidence = (INFERENCE if has_known_bases(parent)
-                          else INFERENCE_FAILURE)
-            name = node.func.name
-            if name == 'property':
-                self.add_message('property-on-old-class', node=node,
-                                 confidence=confidence)
-
-    @check_messages('super-on-old-class', 'bad-super-call', 'missing-super-argument')
+    @check_messages('bad-super-call', 'missing-super-argument')
     def visit_functiondef(self, node):
         """check use of super"""
         # ignore actual functions or method within a new style class
@@ -131,7 +80,7 @@ def visit_functiondef(self, node):
 
             if not klass.newstyle and has_known_bases(klass):
                 # super should not be used on an old style class
-                self.add_message('super-on-old-class', node=node)
+                continue
             else:
                 # super first arg should be the class
                 if not call.args:

pylint/test/input/func_w0233.py

@@ -1,4 +1,5 @@
 # pylint: disable=R0903,W0212,W0403,W0406,no-absolute-import,wrong-import-order, useless-object-inheritance
+
 """test for call to __init__ from a non ancestor class
 """
 from __future__ import print_function

pylint/test/regrtest_data/package/__init__.py

@@ -1,4 +1,5 @@
-# pylint: disable=R0903,W0403,useless-object-inheritance
+# pylint: disable=R0903,W0403
+
 """package's __init__ file"""
 
 from . import subpackage
@@ -8,7 +9,7 @@
 # E0602 - Undefined variable '__path__'
 __path__ += "folder"
 
-class AudioTime(object):
+class AudioTime:
     """test precedence over the AudioTime submodule"""
 
     DECIMAL = 3