diff options
Diffstat (limited to 'pylint/checkers/base.py')
| -rw-r--r-- | pylint/checkers/base.py | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/pylint/checkers/base.py b/pylint/checkers/base.py index 6ce8825..7659fa4 100644 --- a/pylint/checkers/base.py +++ b/pylint/checkers/base.py @@ -508,6 +508,13 @@ functions, methods 'A call of assert on a tuple will always evaluate to true if ' 'the tuple is not empty, and will always evaluate to false if ' 'it is.'), + 'W0124': ('Following "as" with another context manager looks like a tuple.', + 'confusing-with-statement', + 'Emitted when a `with` statement component returns multiple values ' + 'and uses name binding with `as` only for a part of those values, ' + 'as in with ctx() as a, b. This can be misleading, since it\'s not ' + 'clear if the context manager returns a tuple or if the node without ' + 'a name binding is another context manager.'), 'C0121': ('Missing required attribute "%s"', # W0103 'missing-module-attribute', 'Used when an attribute required for modules is missing.'), @@ -872,6 +879,36 @@ functions, methods # everything else is not a proper sequence for reversed() self.add_message('bad-reversed-sequence', node=node) + @check_messages('confusing-with-statement') + def visit_with(self, node): + if not PY3K: + # in Python 2 a "with" statement with multiple managers coresponds + # to multiple nested AST "With" nodes + pairs = [] + parent_node = node.parent + if isinstance(parent_node, astroid.With): + # we only care about the direct parent, since this method + # gets called for each with node anyway + pairs.extend(parent_node.items) + pairs.extend(node.items) + else: + # in PY3K a "with" statement with multiple managers coresponds + # to one AST "With" node with multiple items + pairs = node.items + prev_pair = None + for pair in pairs: + if prev_pair is not None: + if (isinstance(prev_pair[1], astroid.AssName) and + (pair[1] is None and not isinstance(pair[0], astroid.CallFunc))): + # don't emit a message if the second is a function call + # there's no way that can be mistaken for a name assignment + if PY3K or node.lineno == node.parent.lineno: + # if the line number doesn't match + # we assume it's a nested "with" + self.add_message('confusing-with-statement', node=node) + prev_pair = pair + + _NAME_TYPES = { 'module': (MOD_NAME_RGX, 'module'), 'const': (CONST_NAME_RGX, 'constant'), |