vscode-python/pythonFiles/parso/python/errors.py at master · vivlimmsft/vscode-python · GitHub

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# -*- coding: utf-8 -*-

import codecs

import warnings

import re

from contextlib import contextmanager

from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule

from parso.python.tree import search_ancestor

from parso.parser import ParserSyntaxError

_BLOCK_STMTS = ('if_stmt', 'while_stmt', 'for_stmt', 'try_stmt', 'with_stmt')

_STAR_EXPR_PARENTS = ('testlist_star_expr', 'testlist_comp', 'exprlist')

# This is the maximal block size given by python.

_MAX_BLOCK_SIZE = 20

_MAX_INDENT_COUNT = 100

ALLOWED_FUTURES = (

'all_feature_names', 'nested_scopes', 'generators', 'division',

'absolute_import', 'with_statement', 'print_function', 'unicode_literals',

)

def _iter_stmts(scope):

"""

Iterates over all statements and splits up simple_stmt.

"""

for child in scope.children:

if child.type == 'simple_stmt':

for child2 in child.children:

if child2.type == 'newline' or child2 == ';':

continue

yield child2

else:

yield child

def _get_comprehension_type(atom):

first, second = atom.children[:2]

if second.type == 'testlist_comp' and second.children[1].type == 'comp_for':

if first == '[':

return 'list comprehension'

else:

return 'generator expression'

elif second.type == 'dictorsetmaker' and second.children[-1].type == 'comp_for':

if second.children[1] == ':':

return 'dict comprehension'

else:

return 'set comprehension'

return None

def _is_future_import(import_from):

# It looks like a __future__ import that is relative is still a future

# import. That feels kind of odd, but whatever.

# if import_from.level != 0:

# return False

from_names = import_from.get_from_names()

return [n.value for n in from_names] == ['__future__']

def _remove_parens(atom):

"""

Returns the inner part of an expression like `(foo)`. Also removes nested

parens.

"""

try:

children = atom.children

except AttributeError:

pass

else:

if len(children) == 3 and children[0] == '(':

return _remove_parens(atom.children[1])

return atom

def _iter_params(parent_node):

return (n for n in parent_node.children if n.type == 'param')

def _is_future_import_first(import_from):

"""

Checks if the import is the first statement of a file.

"""

found_docstring = False

for stmt in _iter_stmts(import_from.get_root_node()):

if stmt.type == 'string' and not found_docstring:

continue

found_docstring = True

if stmt == import_from:

return True

if stmt.type == 'import_from' and _is_future_import(stmt):

continue

return False

def _iter_definition_exprs_from_lists(exprlist):

for child in exprlist.children[::2]:

if child.type == 'atom' and child.children[0] in ('(', '['):

testlist_comp = child.children[0]

if testlist_comp.type == 'testlist_comp':

for expr in _iter_definition_exprs_from_lists(testlist_comp):

yield expr

continue

elif child.children[0] == '[':

yield testlist_comp

continue

yield child

def _get_expr_stmt_definition_exprs(expr_stmt):

exprs = []

for list_ in expr_stmt.children[:-2:2]:

if list_.type in ('testlist_star_expr', 'testlist'):

exprs += _iter_definition_exprs_from_lists(list_)

else:

exprs.append(list_)

return exprs

def _get_for_stmt_definition_exprs(for_stmt):

exprlist = for_stmt.children[1]

if exprlist.type != 'exprlist':

return [exprlist]

return list(_iter_definition_exprs_from_lists(exprlist))

class _Context(object):

def __init__(self, node, add_syntax_error, parent_context=None):

self.node = node

self.blocks = []

self.parent_context = parent_context

self._used_name_dict = {}

self._global_names = []

self._nonlocal_names = []

self._nonlocal_names_in_subscopes = []

self._add_syntax_error = add_syntax_error

def is_async_funcdef(self):

# Stupidly enough async funcdefs can have two different forms,

# depending if a decorator is used or not.

return self.is_function() \

and self.node.parent.type in ('async_funcdef', 'async_stmt')

def is_function(self):

return self.node.type == 'funcdef'

def add_name(self, name):

parent_type = name.parent.type

if parent_type == 'trailer':

# We are only interested in first level names.

return

if parent_type == 'global_stmt':

self._global_names.append(name)

elif parent_type == 'nonlocal_stmt':

self._nonlocal_names.append(name)

else:

self._used_name_dict.setdefault(name.value, []).append(name)

def finalize(self):

"""

Returns a list of nonlocal names that need to be part of that scope.

"""

self._analyze_names(self._global_names, 'global')

self._analyze_names(self._nonlocal_names, 'nonlocal')

# Python2.6 doesn't have dict comprehensions.

global_name_strs = dict((n.value, n) for n in self._global_names)

for nonlocal_name in self._nonlocal_names:

try:

global_name = global_name_strs[nonlocal_name.value]

except KeyError:

continue

message = "name '%s' is nonlocal and global" % global_name.value

if global_name.start_pos < nonlocal_name.start_pos:

error_name = global_name

else:

error_name = nonlocal_name

self._add_syntax_error(error_name, message)

nonlocals_not_handled = []

for nonlocal_name in self._nonlocal_names_in_subscopes:

search = nonlocal_name.value

if search in global_name_strs or self.parent_context is None:

message = "no binding for nonlocal '%s' found" % nonlocal_name.value

self._add_syntax_error(nonlocal_name, message)

elif not self.is_function() or \

nonlocal_name.value not in self._used_name_dict:

nonlocals_not_handled.append(nonlocal_name)

return self._nonlocal_names + nonlocals_not_handled

def _analyze_names(self, globals_or_nonlocals, type_):

def raise_(message):

self._add_syntax_error(base_name, message % (base_name.value, type_))

params = []

if self.node.type == 'funcdef':

params = self.node.get_params()

for base_name in globals_or_nonlocals:

found_global_or_nonlocal = False

# Somehow Python does it the reversed way.

for name in reversed(self._used_name_dict.get(base_name.value, [])):

if name.start_pos > base_name.start_pos:

# All following names don't have to be checked.

found_global_or_nonlocal = True

parent = name.parent

if parent.type == 'param' and parent.name == name:

# Skip those here, these definitions belong to the next

# scope.

continue

if name.is_definition():

if parent.type == 'expr_stmt' \

and parent.children[1].type == 'annassign':

if found_global_or_nonlocal:

# If it's after the global the error seems to be

# placed there.

base_name = name

raise_("annotated name '%s' can't be %s")

break

else:

message = "name '%s' is assigned to before %s declaration"

else:

message = "name '%s' is used prior to %s declaration"

if not found_global_or_nonlocal:

raise_(message)

# Only add an error for the first occurence.

break

for param in params:

if param.name.value == base_name.value:

raise_("name '%s' is parameter and %s"),

@contextmanager

def add_block(self, node):

self.blocks.append(node)

yield

self.blocks.pop()

def add_context(self, node):

return _Context(node, self._add_syntax_error, parent_context=self)

def close_child_context(self, child_context):

self._nonlocal_names_in_subscopes += child_context.finalize()

class ErrorFinder(Normalizer):

"""

Searches for errors in the syntax tree.

"""

def __init__(self, *args, **kwargs):

super(ErrorFinder, self).__init__(*args, **kwargs)

self._error_dict = {}

self.version = self.grammar.version_info

def initialize(self, node):

def create_context(node):

if node is None:

return None

parent_context = create_context(node.parent)

if node.type in ('classdef', 'funcdef', 'file_input'):

return _Context(node, self._add_syntax_error, parent_context)

return parent_context

self.context = create_context(node) or _Context(node, self._add_syntax_error)

self._indentation_count = 0

def visit(self, node):

if node.type == 'error_node':

with self.visit_node(node):

# Don't need to investigate the inners of an error node. We

# might find errors in there that should be ignored, because

# the error node itself already shows that there's an issue.

return ''

return super(ErrorFinder, self).visit(node)

@contextmanager

def visit_node(self, node):

self._check_type_rules(node)

if node.type in _BLOCK_STMTS:

with self.context.add_block(node):

if len(self.context.blocks) == _MAX_BLOCK_SIZE:

self._add_syntax_error(node, "too many statically nested blocks")

yield

return

elif node.type == 'suite':

self._indentation_count += 1

if self._indentation_count == _MAX_INDENT_COUNT:

self._add_indentation_error(node.children[1], "too many levels of indentation")

yield

if node.type == 'suite':

self._indentation_count -= 1

elif node.type in ('classdef', 'funcdef'):

context = self.context

self.context = context.parent_context

self.context.close_child_context(context)

def visit_leaf(self, leaf):

if leaf.type == 'error_leaf':

if leaf.original_type in ('indent', 'error_dedent'):

# Indents/Dedents itself never have a prefix. They are just

# "pseudo" tokens that get removed by the syntax tree later.

# Therefore in case of an error we also have to check for this.

spacing = list(leaf.get_next_leaf()._split_prefix())[-1]

if leaf.original_type == 'indent':

message = 'unexpected indent'

else:

message = 'unindent does not match any outer indentation level'

self._add_indentation_error(spacing, message)

else:

if leaf.value.startswith('\\'):

message = 'unexpected character after line continuation character'

else:

match = re.match('\\w{,2}("{1,3}|\'{1,3})', leaf.value)

if match is None:

message = 'invalid syntax'

else:

if len(match.group(1)) == 1:

message = 'EOL while scanning string literal'

else:

message = 'EOF while scanning triple-quoted string literal'

self._add_syntax_error(leaf, message)

return ''

elif leaf.value == ':':

parent = leaf.parent

if parent.type in ('classdef', 'funcdef'):

self.context = self.context.add_context(parent)

# The rest is rule based.

return super(ErrorFinder, self).visit_leaf(leaf)

def _add_indentation_error(self, spacing, message):

self.add_issue(spacing, 903, "IndentationError: " + message)

def _add_syntax_error(self, node, message):

self.add_issue(node, 901, "SyntaxError: " + message)

def add_issue(self, node, code, message):

# Overwrite the default behavior.

# Check if the issues are on the same line.

line = node.start_pos[0]

args = (code, message, node)

self._error_dict.setdefault(line, args)

def finalize(self):

self.context.finalize()

for code, message, node in self._error_dict.values():

self.issues.append(Issue(node, code, message))

class IndentationRule(Rule):

code = 903

def _get_message(self, message):

message = super(IndentationRule, self)._get_message(message)

return "IndentationError: " + message

@ErrorFinder.register_rule(type='error_node')

class _ExpectIndentedBlock(IndentationRule):

message = 'expected an indented block'

def get_node(self, node):

leaf = node.get_next_leaf()

return list(leaf._split_prefix())[-1]

def is_issue(self, node):

# This is the beginning of a suite that is not indented.

return node.children[-1].type == 'newline'

class ErrorFinderConfig(NormalizerConfig):

normalizer_class = ErrorFinder

class SyntaxRule(Rule):

code = 901

def _get_message(self, message):

message = super(SyntaxRule, self)._get_message(message)

return "SyntaxError: " + message

@ErrorFinder.register_rule(type='error_node')

class _InvalidSyntaxRule(SyntaxRule):

message = "invalid syntax"

def get_node(self, node):

return node.get_next_leaf()

def is_issue(self, node):

# Error leafs will be added later as an error.

return node.get_next_leaf().type != 'error_leaf'

@ErrorFinder.register_rule(value='await')

class _AwaitOutsideAsync(SyntaxRule):

message = "'await' outside async function"

def is_issue(self, leaf):

return not self._normalizer.context.is_async_funcdef()

def get_error_node(self, node):

# Return the whole await statement.

return node.parent

@ErrorFinder.register_rule(value='break')

class _BreakOutsideLoop(SyntaxRule):

message = "'break' outside loop"

def is_issue(self, leaf):

in_loop = False

for block in self._normalizer.context.blocks:

if block.type in ('for_stmt', 'while_stmt'):

in_loop = True

return not in_loop

@ErrorFinder.register_rule(value='continue')

class _ContinueChecks(SyntaxRule):

message = "'continue' not properly in loop"

message_in_finally = "'continue' not supported inside 'finally' clause"

def is_issue(self, leaf):

in_loop = False

for block in self._normalizer.context.blocks:

if block.type in ('for_stmt', 'while_stmt'):

in_loop = True

if block.type == 'try_stmt':

last_block = block.children[-3]

if last_block == 'finally' and leaf.start_pos > last_block.start_pos:

self.add_issue(leaf, message=self.message_in_finally)

return False # Error already added

if not in_loop:

return True

@ErrorFinder.register_rule(value='from')

class _YieldFromCheck(SyntaxRule):

message = "'yield from' inside async function"

def get_node(self, leaf):

return leaf.parent.parent # This is the actual yield statement.

def is_issue(self, leaf):

return leaf.parent.type == 'yield_arg' \

and self._normalizer.context.is_async_funcdef()

@ErrorFinder.register_rule(type='name')

class _NameChecks(SyntaxRule):

message = 'cannot assign to __debug__'

message_keyword = 'assignment to keyword'

message_none = 'cannot assign to None'

def is_issue(self, leaf):

self._normalizer.context.add_name(leaf)

if leaf.value == '__debug__' and leaf.is_definition():

if self._normalizer.version < (3, 0):

return True

else:

self.add_issue(leaf, message=self.message_keyword)

if leaf.value == 'None' and self._normalizer.version < (3, 0) \

and leaf.is_definition():

self.add_issue(leaf, message=self.message_none)

@ErrorFinder.register_rule(type='string')

class _StringChecks(SyntaxRule):

message = "bytes can only contain ASCII literal characters."

def is_issue(self, leaf):

string_prefix = leaf.string_prefix.lower()

if 'b' in string_prefix \

and self._normalizer.version >= (3, 0) \

and any(c for c in leaf.value if ord(c) > 127):

# b'ä'

return True

if 'r' not in string_prefix:

# Raw strings don't need to be checked if they have proper

# escaping.

is_bytes = self._normalizer.version < (3, 0)

if 'b' in string_prefix:

is_bytes = True

if 'u' in string_prefix:

is_bytes = False

payload = leaf._get_payload()

if is_bytes:

payload = payload.encode('utf-8')

func = codecs.escape_decode

else:

func = codecs.unicode_escape_decode

try:

with warnings.catch_warnings():

# The warnings from parsing strings are not relevant.

warnings.filterwarnings('ignore')

func(payload)

except UnicodeDecodeError as e:

self.add_issue(leaf, message='(unicode error) ' + str(e))

except ValueError as e:

self.add_issue(leaf, message='(value error) ' + str(e))

@ErrorFinder.register_rule(value='*')

class _StarCheck(SyntaxRule):

message = "named arguments must follow bare *"

def is_issue(self, leaf):

params = leaf.parent

if params.type == 'parameters' and params:

after = params.children[params.children.index(leaf) + 1:]

after = [child for child in after

if child not in (',', ')') and not child.star_count]

return len(after) == 0

@ErrorFinder.register_rule(value='**')

class _StarStarCheck(SyntaxRule):

# e.g. {**{} for a in [1]}

# TODO this should probably get a better end_pos including

# the next sibling of leaf.

message = "dict unpacking cannot be used in dict comprehension"

def is_issue(self, leaf):

if leaf.parent.type == 'dictorsetmaker':

comp_for = leaf.get_next_sibling().get_next_sibling()

return comp_for is not None and comp_for.type == 'comp_for'

@ErrorFinder.register_rule(value='yield')

@ErrorFinder.register_rule(value='return')

class _ReturnAndYieldChecks(SyntaxRule):

message = "'return' with value in async generator"

message_async_yield = "'yield' inside async function"

def get_node(self, leaf):

return leaf.parent

def is_issue(self, leaf):

if self._normalizer.context.node.type != 'funcdef':

self.add_issue(self.get_node(leaf), message="'%s' outside function" % leaf.value)

elif self._normalizer.context.is_async_funcdef() \

and any(self._normalizer.context.node.iter_yield_exprs()):

if leaf.value == 'return' and leaf.parent.type == 'return_stmt':

return True

elif leaf.value == 'yield' \

and leaf.get_next_leaf() != 'from' \

and self._normalizer.version == (3, 5):

self.add_issue(self.get_node(leaf), message=self.message_async_yield)

@ErrorFinder.register_rule(type='strings')

class _BytesAndStringMix(SyntaxRule):

# e.g. 's' b''

message = "cannot mix bytes and nonbytes literals"

def _is_bytes_literal(self, string):

return 'b' in string.string_prefix.lower()

def is_issue(self, node):

first = node.children[0]

if first.type == 'string' and self._normalizer.version >= (3, 0):

first_is_bytes = self._is_bytes_literal(first)

for string in node.children[1:]:

if first_is_bytes != self._is_bytes_literal(string):

return True

@ErrorFinder.register_rule(type='import_as_names')

class _TrailingImportComma(SyntaxRule):

# e.g. from foo import a,

message = "trailing comma not allowed without surrounding parentheses"

def is_issue(self, node):

if node.children[-1] == ',':

return True

@ErrorFinder.register_rule(type='import_from')

class _ImportStarInFunction(SyntaxRule):

message = "import * only allowed at module level"

def is_issue(self, node):

return node.is_star_import() and self._normalizer.context.parent_context is not None

@ErrorFinder.register_rule(type='import_from')

class _FutureImportRule(SyntaxRule):

message = "from __future__ imports must occur at the beginning of the file"

def is_issue(self, node):

if _is_future_import(node):

if not _is_future_import_first(node):

return True

for from_name, future_name in node.get_paths():

name = future_name.value

allowed_futures = list(ALLOWED_FUTURES)

if self._normalizer.version >= (3, 5):

allowed_futures.append('generator_stop')

if name == 'braces':

self.add_issue(node, message = "not a chance")

elif name == 'barry_as_FLUFL':

m = "Seriously I'm not implementing this :) ~ Dave"

self.add_issue(node, message=m)

elif name not in ALLOWED_FUTURES:

message = "future feature %s is not defined" % name

self.add_issue(node, message=message)

@ErrorFinder.register_rule(type='star_expr')

class _StarExprRule(SyntaxRule):

message = "starred assignment target must be in a list or tuple"

message_iterable_unpacking = "iterable unpacking cannot be used in comprehension"

message_assignment = "can use starred expression only as assignment target"

def is_issue(self, node):

if node.parent.type not in _STAR_EXPR_PARENTS:

return True

if node.parent.type == 'testlist_comp':

# [*[] for a in [1]]

if node.parent.children[1].type == 'comp_for':

self.add_issue(node, message=self.message_iterable_unpacking)

if self._normalizer.version <= (3, 4):

n = search_ancestor(node, 'for_stmt', 'expr_stmt')

found_definition = False

if n is not None:

if n.type == 'expr_stmt':

exprs = _get_expr_stmt_definition_exprs(n)

else:

exprs = _get_for_stmt_definition_exprs(n)

if node in exprs:

found_definition = True

if not found_definition:

self.add_issue(node, message=self.message_assignment)

@ErrorFinder.register_rule(types=_STAR_EXPR_PARENTS)

class _StarExprParentRule(SyntaxRule):

def is_issue(self, node):

if node.parent.type == 'del_stmt':

self.add_issue(node.parent, message="can't use starred expression here")

else:

def is_definition(node, ancestor):

if ancestor is None:

return False

type_ = ancestor.type

if type_ == 'trailer':

return False

if type_ == 'expr_stmt':

return node.start_pos < ancestor.children[-1].start_pos

return is_definition(node, ancestor.parent)

if is_definition(node, node.parent):

args = [c for c in node.children if c != ',']

starred = [c for c in args if c.type == 'star_expr']

if len(starred) > 1:

message = "two starred expressions in assignment"

self.add_issue(starred[1], message=message)

elif starred:

count = args.index(starred[0])

if count >= 256:

message = "too many expressions in star-unpacking assignment"

self.add_issue(starred[0], message=message)

@ErrorFinder.register_rule(type='annassign')

class _AnnotatorRule(SyntaxRule):

# True: int

# {}: float

message = "illegal target for annotation"

def get_node(self, node):

return node.parent

def is_issue(self, node):

type_ = None

lhs = node.parent.children[0]

lhs = _remove_parens(lhs)

try:

children = lhs.children

except AttributeError:

pass

else:

if ',' in children or lhs.type == 'atom' and children[0] == '(':

type_ = 'tuple'

elif lhs.type == 'atom' and children[0] == '[':

type_ = 'list'

trailer = children[-1]

if type_ is None:

if not (lhs.type == 'name'

# subscript/attributes are allowed

or lhs.type in ('atom_expr', 'power')

and trailer.type == 'trailer'

and trailer.children[0] != '('):

return True

else:

# x, y: str

message = "only single target (not %s) can be annotated"

self.add_issue(lhs.parent, message=message % type_)

@ErrorFinder.register_rule(type='argument')

class _ArgumentRule(SyntaxRule):

def is_issue(self, node):

first = node.children[0]

if node.children[1] == '=' and first.type != 'name':

if first.type == 'lambdef':

# f(lambda: 1=1)

message = "lambda cannot contain assignment"

else:

# f(+x=1)

message = "keyword can't be an expression"

self.add_issue(first, message=message)

@ErrorFinder.register_rule(type='nonlocal_stmt')

class _NonlocalModuleLevelRule(SyntaxRule):

message = "nonlocal declaration not allowed at module level"

def is_issue(self, node):

return self._normalizer.context.parent_context is None

@ErrorFinder.register_rule(type='arglist')

class _ArglistRule(SyntaxRule):

@property

def message(self):

if self._normalizer.version < (3, 7):

return "Generator expression must be parenthesized if not sole argument"

else:

return "Generator expression must be parenthesized"

def is_issue(self, node):

first_arg = node.children[0]

if first_arg.type == 'argument' \

and first_arg.children[1].type == 'comp_for':

# e.g. foo(x for x in [], b)

return len(node.children) >= 2

else:

arg_set = set()

kw_only = False

kw_unpacking_only = False

is_old_starred = False

# In python 3 this would be a bit easier (stars are part of

# argument), but we have to understand both.

for argument in node.children:

if argument == ',':

continue

if argument in ('*', '**'):

# Python < 3.5 has the order engraved in the grammar

# file. No need to do anything here.

is_old_starred = True

continue

if is_old_starred:

is_old_starred = False

continue

if argument.type == 'argument':

first = argument.children[0]

if first in ('*', '**'):

if first == '*':

if kw_unpacking_only:

# foo(**kwargs, *args)

message = "iterable argument unpacking follows keyword argument unpacking"

self.add_issue(argument, message=message)

else:

kw_unpacking_only = True

else: # Is a keyword argument.

kw_only = True

if first.type == 'name':

if first.value in arg_set:

# f(x=1, x=2)

self.add_issue(first, message="keyword argument repeated")

else:

arg_set.add(first.value)

else:

if kw_unpacking_only:

# f(**x, y)

message = "positional argument follows keyword argument unpacking"

self.add_issue(argument, message=message)

elif kw_only:

# f(x=2, y)

message = "positional argument follows keyword argument"

self.add_issue(argument, message=message)

@ErrorFinder.register_rule(type='parameters')

@ErrorFinder.register_rule(type='lambdef')

class _ParameterRule(SyntaxRule):

# def f(x=3, y): pass

message = "non-default argument follows default argument"

def is_issue(self, node):

param_names = set()

default_only = False

for p in _iter_params(node):

if p.name.value in param_names:

message = "duplicate argument '%s' in function definition"

self.add_issue(p.name, message=message % p.name.value)

param_names.add(p.name.value)

if p.default is None and not p.star_count:

if default_only:

return True

else:

default_only = True

@ErrorFinder.register_rule(type='try_stmt')

class _TryStmtRule(SyntaxRule):

message = "default 'except:' must be last"

def is_issue(self, try_stmt):

default_except = None

for except_clause in try_stmt.children[3::3]:

if except_clause in ('else', 'finally'):

break

if except_clause == 'except':

default_except = except_clause

elif default_except is not None:

self.add_issue(default_except, message=self.message)

@ErrorFinder.register_rule(type='fstring')

class _FStringRule(SyntaxRule):

_fstring_grammar = None

message_nested = "f-string: expressions nested too deeply"

message_conversion = "f-string: invalid conversion character: expected 's', 'r', or 'a'"

def _check_format_spec(self, format_spec, depth):

self._check_fstring_contents(format_spec.children[1:], depth)

def _check_fstring_expr(self, fstring_expr, depth):

if depth >= 2:

self.add_issue(fstring_expr, message=self.message_nested)

conversion = fstring_expr.children[2]

if conversion.type == 'fstring_conversion':

name = conversion.children[1]

if name.value not in ('s', 'r', 'a'):

self.add_issue(name, message=self.message_conversion)

format_spec = fstring_expr.children[-2]

if format_spec.type == 'fstring_format_spec':

self._check_format_spec(format_spec, depth + 1)

def is_issue(self, fstring):

self._check_fstring_contents(fstring.children[1:-1])

def _check_fstring_contents(self, children, depth=0):

for fstring_content in children:

if fstring_content.type == 'fstring_expr':

self._check_fstring_expr(fstring_content, depth)

class _CheckAssignmentRule(SyntaxRule):

def _check_assignment(self, node, is_deletion=False):

error = None

type_ = node.type

if type_ == 'lambdef':

error = 'lambda'

elif type_ == 'atom':

first, second = node.children[:2]

error = _get_comprehension_type(node)

if error is None:

if second.type == 'dictorsetmaker':

error = 'literal'

elif first in ('(', '['):

if second.type == 'yield_expr':

error = 'yield expression'

elif second.type == 'testlist_comp':

# This is not a comprehension, they were handled

# further above.

for child in second.children[::2]:

self._check_assignment(child, is_deletion)

else: # Everything handled, must be useless brackets.

self._check_assignment(second, is_deletion)

elif type_ == 'keyword':

error = 'keyword'

elif type_ == 'operator':

if node.value == '...':

error = 'Ellipsis'

elif type_ == 'comparison':

error = 'comparison'

elif type_ in ('string', 'number', 'strings'):

error = 'literal'

elif type_ == 'yield_expr':

# This one seems to be a slightly different warning in Python.

message = 'assignment to yield expression not possible'

self.add_issue(node, message=message)

elif type_ == 'test':

error = 'conditional expression'

elif type_ in ('atom_expr', 'power'):

if node.children[0] == 'await':

error = 'await expression'

elif node.children[-2] == '**':

error = 'operator'

else:

# Has a trailer

trailer = node.children[-1]

assert trailer.type == 'trailer'

if trailer.children[0] == '(':

error = 'function call'

elif type_ in ('testlist_star_expr', 'exprlist', 'testlist'):

for child in node.children[::2]:

self._check_assignment(child, is_deletion)

elif ('expr' in type_ and type_ != 'star_expr' # is a substring

or '_test' in type_

or type_ in ('term', 'factor')):

error = 'operator'

if error is not None:

message = "can't %s %s" % ("delete" if is_deletion else "assign to", error)

self.add_issue(node, message=message)

@ErrorFinder.register_rule(type='comp_for')

class _CompForRule(_CheckAssignmentRule):

message = "asynchronous comprehension outside of an asynchronous function"

def is_issue(self, node):

# Some of the nodes here are already used, so no else if

expr_list = node.children[1 + int(node.children[0] == 'async')]

if expr_list.type != 'expr_list': # Already handled.

self._check_assignment(expr_list)

return node.children[0] == 'async' \

and not self._normalizer.context.is_async_funcdef()

@ErrorFinder.register_rule(type='expr_stmt')

class _ExprStmtRule(_CheckAssignmentRule):

message = "illegal expression for augmented assignment"

def is_issue(self, node):

for before_equal in node.children[:-2:2]:

self._check_assignment(before_equal)

augassign = node.children[1]

if augassign != '=' and augassign.type != 'annassign': # Is augassign.

return node.children[0].type in ('testlist_star_expr', 'atom', 'testlist')

@ErrorFinder.register_rule(type='with_item')

class _WithItemRule(_CheckAssignmentRule):

def is_issue(self, with_item):

self._check_assignment(with_item.children[2])

@ErrorFinder.register_rule(type='del_stmt')

class _DelStmtRule(_CheckAssignmentRule):

def is_issue(self, del_stmt):

child = del_stmt.children[1]

if child.type != 'expr_list': # Already handled.

self._check_assignment(child, is_deletion=True)

@ErrorFinder.register_rule(type='expr_list')

class _ExprListRule(_CheckAssignmentRule):

def is_issue(self, expr_list):

for expr in expr_list.children[::2]:

self._check_assignment(expr)

@ErrorFinder.register_rule(type='for_stmt')

class _ForStmtRule(_CheckAssignmentRule):

def is_issue(self, for_stmt):

# Some of the nodes here are already used, so no else if

expr_list = for_stmt.children[1]

if expr_list.type != 'expr_list': # Already handled.

self._check_assignment(expr_list)

vscode-python/pythonFiles/parso/python/errors.py at master · vivlimmsft/vscode-python · GitHub

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