Some small changes to the changelog

The test had changed behavior for Python 3.8, a syntax error of:

SyntaxError: unexpected EOF while parsing

instead of

SyntaxError: invalid syntax

CHANGELOG.rst

@@ -3,6 +3,14 @@
 Changelog
 ---------
 
+0.5.0 (2019-06-20)
+++++++++++++++++++
+
+- **Breaking Change** comp_for is now called sync_comp_for for all Python
+  versions to be compatible with the Python 3.8 Grammar
+- Added .pyi stubs for a lot of the parso API
+- Small FileIO changes
+
 0.4.0 (2019-04-05)
 ++++++++++++++++++
 

conftest.py

@@ -14,7 +14,7 @@ from parso.utils import parse_version_string
 collect_ignore = ["setup.py"]
 
 VERSIONS_2 = '2.6', '2.7'
-VERSIONS_3 = '3.3', '3.4', '3.5', '3.6', '3.7'
+VERSIONS_3 = '3.3', '3.4', '3.5', '3.6', '3.7', '3.8'
 
 
 @pytest.fixture(scope='session')
@@ -155,3 +155,9 @@ def works_ge_py3(each_version):
 def works_ge_py35(each_version):
     version_info = parse_version_string(each_version)
     return Checker(each_version, version_info >= (3, 5))
+
+
+@pytest.fixture
+def works_ge_py38(each_version):
+    version_info = parse_version_string(each_version)
+    return Checker(each_version, version_info >= (3, 8))

parso/__init__.py

@@ -43,7 +43,7 @@ from parso.grammar import Grammar, load_grammar
 from parso.utils import split_lines, python_bytes_to_unicode
 
 
-__version__ = '0.4.0'
+__version__ = '0.5.0'
 
 
 def parse(code=None, **kwargs):

parso/__init__.pyi

@@ -0,0 +1,19 @@
+from typing import Any, Optional, Union
+
+from parso.grammar import Grammar as Grammar, load_grammar as load_grammar
+from parso.parser import ParserSyntaxError as ParserSyntaxError
+from parso.utils import python_bytes_to_unicode as python_bytes_to_unicode, split_lines as split_lines
+
+__version__: str = ...
+
+def parse(
+    code: Optional[Union[str, bytes]],
+    *,
+    version: Optional[str] = None,
+    error_recovery: bool = True,
+    path: Optional[str] = None,
+    start_symbol: Optional[str] = None,
+    cache: bool = False,
+    diff_cache: bool = False,
+    cache_path: Optional[str] = None,
+) -> Any: ...

parso/cache.py

@@ -18,7 +18,7 @@ from parso._compatibility import FileNotFoundError
 LOG = logging.getLogger(__name__)
 
 
-_PICKLE_VERSION = 31
+_PICKLE_VERSION = 32
 """
 Version number (integer) for file system cache.
 
@@ -82,9 +82,8 @@ def load_module(hashed_grammar, file_io, cache_path=None):
     """
     Returns a module or None, if it fails.
     """
-    try:
-        p_time = file_io.get_last_modified()
-    except FileNotFoundError:
+    p_time = file_io.get_last_modified()
+    if p_time is None:
         return None
 
     try:

parso/file_io.py

@@ -14,10 +14,13 @@ class FileIO(object):
 
     def get_last_modified(self):
         """
-        Returns float - timestamp
-        Might raise FileNotFoundError
+        Returns float - timestamp or None, if path doesn't exist.
         """
-        return os.path.getmtime(self.path)
+        try:
+            return os.path.getmtime(self.path)
+        except OSError:
+            # Might raise FileNotFoundError, OSError for Python 2
+            return None
 
     def __repr__(self):
         return '%s(%s)' % (self.__class__.__name__, self.path)

parso/grammar.pyi

@@ -0,0 +1,38 @@
+from typing import Any, Callable, Generic, Optional, Sequence, TypeVar, Union
+from typing_extensions import Literal
+
+from parso.utils import PythonVersionInfo
+
+_Token = Any
+_NodeT = TypeVar("_NodeT")
+
+class Grammar(Generic[_NodeT]):
+    _default_normalizer_config: Optional[Any] = ...
+    _error_normalizer_config: Optional[Any] = None
+    _start_nonterminal: str = ...
+    _token_namespace: Optional[str] = None
+    def __init__(
+        self,
+        text: str,
+        tokenizer: Callable[[Sequence[str], int], Sequence[_Token]],
+        parser: Any = ...,
+        diff_parser: Any = ...,
+    ) -> None: ...
+    def parse(
+        self,
+        code: Union[str, bytes] = ...,
+        error_recovery: bool = ...,
+        path: Optional[str] = ...,
+        start_symbol: Optional[str] = ...,
+        cache: bool = ...,
+        diff_cache: bool = ...,
+        cache_path: Optional[str] = ...,
+    ) -> _NodeT: ...
+
+class PythonGrammar(Grammar):
+    version_info: PythonVersionInfo
+    def __init__(self, version_info: PythonVersionInfo, bnf_text: str) -> None: ...
+
+def load_grammar(
+    language: Literal["python"] = "python", version: Optional[str] = ..., path: str = ...
+) -> Grammar: ...

parso/normalizer.py

@@ -41,8 +41,8 @@ class Normalizer(use_metaclass(_NormalizerMeta)):
         except AttributeError:
             return self.visit_leaf(node)
         else:
-           with self.visit_node(node):
-               return ''.join(self.visit(child) for child in children)
+            with self.visit_node(node):
+                return ''.join(self.visit(child) for child in children)
 
     @contextmanager
     def visit_node(self, node):
@@ -147,7 +147,6 @@ class Issue(object):
         return '<%s: %s>' % (self.__class__.__name__, self.code)
 
 
-
 class Rule(object):
     code = None
     message = None

parso/pgen2/__init__.pyi

@@ -0,0 +1 @@
+from parso.pgen2.generator import generate_grammar as generate_grammar

parso/pgen2/generator.pyi

@@ -0,0 +1,38 @@
+from typing import Any, Generic, Mapping, Sequence, Set, TypeVar, Union
+
+from parso.pgen2.grammar_parser import NFAState
+
+_TokenTypeT = TypeVar("_TokenTypeT")
+
+class Grammar(Generic[_TokenTypeT]):
+    nonterminal_to_dfas: Mapping[str, Sequence[DFAState[_TokenTypeT]]]
+    reserved_syntax_strings: Mapping[str, ReservedString]
+    start_nonterminal: str
+    def __init__(
+        self,
+        start_nonterminal: str,
+        rule_to_dfas: Mapping[str, Sequence[DFAState]],
+        reserved_syntax_strings: Mapping[str, ReservedString],
+    ) -> None: ...
+
+class DFAPlan:
+    next_dfa: DFAState
+    dfa_pushes: Sequence[DFAState]
+
+class DFAState(Generic[_TokenTypeT]):
+    from_rule: str
+    nfa_set: Set[NFAState]
+    is_final: bool
+    arcs: Mapping[str, DFAState]  # map from all terminals/nonterminals to DFAState
+    nonterminal_arcs: Mapping[str, DFAState]
+    transitions: Mapping[Union[_TokenTypeT, ReservedString], DFAPlan]
+    def __init__(
+        self, from_rule: str, nfa_set: Set[NFAState], final: NFAState
+    ) -> None: ...
+
+class ReservedString:
+    value: str
+    def __init__(self, value: str) -> None: ...
+    def __repr__(self) -> str: ...
+
+def generate_grammar(bnf_grammar: str, token_namespace: Any) -> Grammar[Any]: ...

parso/pgen2/grammar_parser.pyi

@@ -0,0 +1,20 @@
+from typing import Generator, List, Optional, Tuple
+
+from parso.python.token import TokenType
+
+class GrammarParser:
+    generator: Generator[TokenType, None, None]
+    def __init__(self, bnf_grammar: str) -> None: ...
+    def parse(self) -> Generator[Tuple[NFAState, NFAState], None, None]: ...
+
+class NFAArc:
+    next: NFAState
+    nonterminal_or_string: Optional[str]
+    def __init__(
+        self, next_: NFAState, nonterminal_or_string: Optional[str]
+    ) -> None: ...
+
+class NFAState:
+    from_rule: str
+    arcs: List[NFAArc]
+    def __init__(self, from_rule: str) -> None: ...

parso/python/errors.py

@@ -953,20 +953,17 @@ class _CheckAssignmentRule(SyntaxRule):
             self.add_issue(node, message=message)
 
 
-@ErrorFinder.register_rule(type='comp_for')
 @ErrorFinder.register_rule(type='sync_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
-        if node.type != 'comp_for' or self._normalizer.version < (3, 8):
-            # comp_for was replaced by sync_comp_for in Python 3.8.
-            expr_list = node.children[1 + int(node.children[0] == 'async')]
-            if expr_list.type != 'expr_list':  # Already handled.
-                self._check_assignment(expr_list)
+        expr_list = node.children[1]
+        print(expr_list)
+        if expr_list.type != 'expr_list':  # Already handled.
+            self._check_assignment(expr_list)
 
-        return node.children[0] == 'async' \
+        return node.parent.children[0] == 'async' \
             and not self._normalizer.context.is_async_funcdef()
 
 

parso/python/grammar27.txt

@@ -107,7 +107,7 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        NAME | NUMBER | strings)
 strings: STRING+
 listmaker: test ( list_for | (',' test)* [','] )
-testlist_comp: test ( comp_for | (',' test)* [','] )
+testlist_comp: test ( sync_comp_for | (',' test)* [','] )
 lambdef: 'lambda' [varargslist] ':' test
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
@@ -115,8 +115,8 @@ subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: expr (',' expr)* [',']
 testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
+dictorsetmaker: ( (test ':' test (sync_comp_for | (',' test ':' test)* [','])) |
+                  (test (sync_comp_for | (',' test)* [','])) )
 
 classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
 
@@ -125,14 +125,14 @@ arglist: (argument ',')* (argument [',']
                          |'**' test)
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test
+argument: test [sync_comp_for] | test '=' test
 
 list_iter: list_for | list_if
 list_for: 'for' exprlist 'in' testlist_safe [list_iter]
 list_if: 'if' old_test [list_iter]
 
-comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_iter: sync_comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
 comp_if: 'if' old_test [comp_iter]
 
 testlist1: test (',' test)*

parso/python/grammar33.txt

@@ -105,15 +105,15 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '{' [dictorsetmaker] '}' |
        NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
 strings: STRING+
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+testlist_comp: (test|star_expr) ( sync_comp_for | (',' (test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
+dictorsetmaker: ( (test ':' test (sync_comp_for | (',' test ':' test)* [','])) |
+                  (test (sync_comp_for | (',' test)* [','])) )
 
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
@@ -122,9 +122,9 @@ arglist: (argument ',')* (argument [',']
                          |'**' test)
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test  # Really [keyword '='] test
-comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+argument: test [sync_comp_for] | test '=' test  # Really [keyword '='] test
+comp_iter: sync_comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler

parso/python/grammar34.txt

@@ -105,15 +105,15 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '{' [dictorsetmaker] '}' |
        NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
 strings: STRING+
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+testlist_comp: (test|star_expr) ( sync_comp_for | (',' (test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
+dictorsetmaker: ( (test ':' test (sync_comp_for | (',' test ':' test)* [','])) |
+                  (test (sync_comp_for | (',' test)* [','])) )
 
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
@@ -122,9 +122,9 @@ arglist: (argument ',')* (argument [',']
                          |'**' test)
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test  # Really [keyword '='] test
-comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+argument: test [sync_comp_for] | test '=' test  # Really [keyword '='] test
+comp_iter: sync_comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler

parso/python/grammar35.txt

@@ -112,7 +112,7 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '{' [dictorsetmaker] '}' |
        NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
 strings: STRING+
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+testlist_comp: (test|star_expr) ( sync_comp_for | (',' (test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
@@ -120,9 +120,9 @@ sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
 dictorsetmaker: ( ((test ':' test | '**' expr)
-                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                   (sync_comp_for | (',' (test ':' test | '**' expr))* [','])) |
                   ((test | star_expr)
-                   (comp_for | (',' (test | star_expr))* [','])) )
+                   (sync_comp_for | (',' (test | star_expr))* [','])) )
 
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
@@ -137,13 +137,13 @@ arglist: argument (',' argument)*  [',']
 # Illegal combinations and orderings are blocked in ast.c:
 # multiple (test comp_for) arguments are blocked; keyword unpackings
 # that precede iterable unpackings are blocked; etc.
-argument: ( test [comp_for] |
+argument: ( test [sync_comp_for] |
             test '=' test |
             '**' test |
             '*' test )
 
-comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_iter: sync_comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler

parso/python/grammar36.txt

@@ -140,7 +140,8 @@ argument: ( test [comp_for] |
             '*' test )
 
 comp_iter: comp_for | comp_if
-comp_for: ['async'] 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler

parso/python/grammar37.txt

@@ -138,7 +138,8 @@ argument: ( test [comp_for] |
             '*' test )
 
 comp_iter: comp_for | comp_if
-comp_for: ['async'] 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler

parso/python/grammar38.txt

@@ -20,13 +20,25 @@ async_funcdef: 'async' funcdef
 funcdef: 'def' NAME parameters ['->' test] ':' suite
 
 parameters: '(' [typedargslist] ')'
-typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+typedargslist: (
+  (tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [',' [ tfpdef ['=' test] (
+        ',' tfpdef ['=' test])* ([',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]])
+  | '*' [tfpdef] (',' tfpdef ['=' test])* ([',' ['**' tfpdef [',']]])
+  | '**' tfpdef [',']]] )
+|  (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
         '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
       | '**' tfpdef [',']]]
   | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
   | '**' tfpdef [','])
+)
 tfpdef: NAME [':' test]
-varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']) ]] | (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
         '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
       | '**' vfpdef [',']]]
   | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
@@ -69,8 +81,8 @@ assert_stmt: 'assert' test [',' test]
 
 compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
 async_stmt: 'async' (funcdef | with_stmt | for_stmt)
-if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
-while_stmt: 'while' test ':' suite ['else' ':' suite]
+if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
 for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
 try_stmt: ('try' ':' suite
            ((except_clause ':' suite)+
@@ -83,6 +95,7 @@ with_item: test ['as' expr]
 except_clause: 'except' [test ['as' NAME]]
 suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
 
+namedexpr_test: test [':=' test]
 test: or_test ['if' or_test 'else' test] | lambdef
 test_nocond: or_test | lambdef_nocond
 lambdef: 'lambda' [varargslist] ':' test
@@ -108,7 +121,7 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |
        NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+testlist_comp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
@@ -134,6 +147,7 @@ arglist: argument (',' argument)*  [',']
 # multiple (test comp_for) arguments are blocked; keyword unpackings
 # that precede iterable unpackings are blocked; etc.
 argument: ( test [comp_for] |
+            test ':=' test |
             test '=' test |
             '**' test |
             '*' test )
@@ -153,5 +167,5 @@ strings: (STRING | fstring)+
 fstring: FSTRING_START fstring_content* FSTRING_END
 fstring_content: FSTRING_STRING | fstring_expr
 fstring_conversion: '!' NAME
-fstring_expr: '{' testlist [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_expr: '{' testlist ['='] [ fstring_conversion ] [ fstring_format_spec ] '}'
 fstring_format_spec: ':' fstring_content*

parso/python/parser.py

@@ -39,13 +39,13 @@ class Parser(BaseParser):
         'for_stmt': tree.ForStmt,
         'while_stmt': tree.WhileStmt,
         'try_stmt': tree.TryStmt,
-        'comp_for': tree.CompFor,
+        'sync_comp_for': tree.SyncCompFor,
         # Not sure if this is the best idea, but IMO it's the easiest way to
         # avoid extreme amounts of work around the subtle difference of 2/3
         # grammar in list comoprehensions.
-        'list_for': tree.CompFor,
+        'list_for': tree.SyncCompFor,
         # Same here. This just exists in Python 2.6.
-        'gen_for': tree.CompFor,
+        'gen_for': tree.SyncCompFor,
         'decorator': tree.Decorator,
         'lambdef': tree.Lambda,
         'old_lambdef': tree.Lambda,

parso/python/token.pyi

@@ -0,0 +1,30 @@
+from typing import Container, Iterable
+
+class TokenType:
+    name: str
+    contains_syntax: bool
+    def __init__(self, name: str, contains_syntax: bool) -> None: ...
+
+class TokenTypes:
+    def __init__(
+        self, names: Iterable[str], contains_syntax: Container[str]
+    ) -> None: ...
+
+# not an actual class in the source code, but we need this class to type the fields of
+# PythonTokenTypes
+class _FakePythonTokenTypesClass(TokenTypes):
+    STRING: TokenType
+    NUMBER: TokenType
+    NAME: TokenType
+    ERRORTOKEN: TokenType
+    NEWLINE: TokenType
+    INDENT: TokenType
+    DEDENT: TokenType
+    ERROR_DEDENT: TokenType
+    FSTRING_STRING: TokenType
+    FSTRING_START: TokenType
+    FSTRING_END: TokenType
+    OP: TokenType
+    ENDMARKER: TokenType
+
+PythonTokenTypes: _FakePythonTokenTypesClass = ...

parso/python/tokenize.py

@@ -120,6 +120,8 @@ def _get_token_collection(version_info):
 
 fstring_string_single_line = _compile(r'(?:[^{}\r\n]+|\{\{|\}\})+')
 fstring_string_multi_line = _compile(r'(?:[^{}]+|\{\{|\}\})+')
+fstring_format_spec_single_line = _compile(r'[^{}\r\n]+')
+fstring_format_spec_multi_line = _compile(r'[^{}]+')
 
 
 def _create_token_collection(version_info):
@@ -151,6 +153,8 @@ def _create_token_collection(version_info):
             Octnumber = '0[oO]?[0-7]+'
         Decnumber = r'(?:0+|[1-9][0-9]*)'
         Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
+        if version_info[0] < 3:
+            Intnumber += '[lL]?'
         Exponent = r'[eE][-+]?[0-9]+'
         Pointfloat = group(r'[0-9]+\.[0-9]*', r'\.[0-9]+') + maybe(Exponent)
         Expfloat = r'[0-9]+' + Exponent
@@ -186,9 +190,13 @@ def _create_token_collection(version_info):
 
     Bracket = '[][(){}]'
 
-    special_args = [r'\r\n?', r'\n', r'[:;.,@]']
+    special_args = [r'\r\n?', r'\n', r'[;.,@]']
     if version_info >= (3, 0):
         special_args.insert(0, r'\.\.\.')
+    if version_info >= (3, 8):
+        special_args.insert(0, ":=?")
+    else:
+        special_args.insert(0, ":")
     Special = group(*special_args)
 
     Funny = group(Operator, Bracket, Special)
@@ -281,7 +289,10 @@ class FStringNode(object):
         return len(self.quote) == 3
 
     def is_in_expr(self):
-        return (self.parentheses_count - self.format_spec_count) > 0
+        return self.parentheses_count > self.format_spec_count
+
+    def is_in_format_spec(self):
+        return not self.is_in_expr() and self.format_spec_count
 
 
 def _close_fstring_if_necessary(fstring_stack, string, start_pos, additional_prefix):
@@ -303,10 +314,18 @@ def _close_fstring_if_necessary(fstring_stack, string, start_pos, additional_pre
 def _find_fstring_string(endpats, fstring_stack, line, lnum, pos):
     tos = fstring_stack[-1]
     allow_multiline = tos.allow_multiline()
-    if allow_multiline:
-        match = fstring_string_multi_line.match(line, pos)
+    if tos.is_in_format_spec():
+        if allow_multiline:
+            regex = fstring_format_spec_multi_line
+        else:
+            regex = fstring_format_spec_single_line
     else:
-        match = fstring_string_single_line.match(line, pos)
+        if allow_multiline:
+            regex = fstring_string_multi_line
+        else:
+            regex = fstring_string_single_line
+
+    match = regex.match(line, pos)
     if match is None:
         return tos.previous_lines, pos
 
@@ -575,7 +594,8 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
                         if paren_level:
                             paren_level -= 1
                 elif token == ':' and fstring_stack \
-                        and fstring_stack[-1].parentheses_count == 1:
+                        and fstring_stack[-1].parentheses_count \
+                        - fstring_stack[-1].format_spec_count == 1:
                     fstring_stack[-1].format_spec_count += 1
 
                 yield PythonToken(OP, token, spos, prefix)

parso/python/tokenize.pyi

@@ -0,0 +1,24 @@
+from typing import Generator, Iterable, NamedTuple, Tuple
+
+from parso.python.token import TokenType
+from parso.utils import PythonVersionInfo
+
+class Token(NamedTuple):
+    type: TokenType
+    string: str
+    start_pos: Tuple[int, int]
+    prefix: str
+    @property
+    def end_pos(self) -> Tuple[int, int]: ...
+
+class PythonToken(Token):
+    def __repr__(self) -> str: ...
+
+def tokenize(
+    code: str, version_info: PythonVersionInfo, start_pos: Tuple[int, int] = (1, 0)
+) -> Generator[PythonToken, None, None]: ...
+def tokenize_lines(
+    lines: Iterable[str],
+    version_info: PythonVersionInfo,
+    start_pos: Tuple[int, int] = (1, 0),
+) -> Generator[PythonToken, None, None]: ...

parso/python/tree.py

@@ -43,6 +43,7 @@ Parser Tree Classes
 """
 
 import re
+from collections import Mapping
 
 from parso._compatibility import utf8_repr, unicode
 from parso.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf, \
@@ -55,7 +56,7 @@ _FLOW_CONTAINERS = set(['if_stmt', 'while_stmt', 'for_stmt', 'try_stmt',
 _RETURN_STMT_CONTAINERS = set(['suite', 'simple_stmt']) | _FLOW_CONTAINERS
 _FUNC_CONTAINERS = set(['suite', 'simple_stmt', 'decorated']) | _FLOW_CONTAINERS
 _GET_DEFINITION_TYPES = set([
-    'expr_stmt', 'comp_for', 'with_stmt', 'for_stmt', 'import_name',
+    'expr_stmt', 'sync_comp_for', 'with_stmt', 'for_stmt', 'import_name',
     'import_from', 'param'
 ])
 _IMPORTS = set(['import_name', 'import_from'])
@@ -442,7 +443,7 @@ class Module(Scope):
                         recurse(child)
 
             recurse(self)
-            self._used_names = dct
+            self._used_names = UsedNamesMapping(dct)
         return self._used_names
 
 
@@ -466,6 +467,9 @@ class ClassOrFunc(Scope):
         :rtype: list of :class:`Decorator`
         """
         decorated = self.parent
+        if decorated.type == 'async_funcdef':
+            decorated = decorated.parent
+
         if decorated.type == 'decorated':
             if decorated.children[0].type == 'decorators':
                 return decorated.children[0].children
@@ -545,7 +549,8 @@ def _create_params(parent, argslist_list):
                     if param_children[0] == '*' \
                             and (len(param_children) == 1
                                  or param_children[1] == ',') \
-                            or check_python2_nested_param(param_children[0]):
+                            or check_python2_nested_param(param_children[0]) \
+                            or param_children[0] == '/':
                         for p in param_children:
                             p.parent = parent
                         new_children += param_children
@@ -1158,6 +1163,13 @@ class Param(PythonBaseNode):
                 index -= 2
         except ValueError:
             pass
+        try:
+            keyword_only_index = self.parent.children.index('/')
+            if index > keyword_only_index:
+                # Skip the ` /, `
+                index -= 2
+        except ValueError:
+            pass
         return index - 1
 
     def get_parent_function(self):
@@ -1189,8 +1201,8 @@ class Param(PythonBaseNode):
         return '<%s: %s>' % (type(self).__name__, str(self._tfpdef()) + default)
 
 
-class CompFor(PythonBaseNode):
-    type = 'comp_for'
+class SyncCompFor(PythonBaseNode):
+    type = 'sync_comp_for'
     __slots__ = ()
 
     def get_defined_names(self):
@@ -1198,4 +1210,33 @@ class CompFor(PythonBaseNode):
         Returns the a list of `Name` that the comprehension defines.
         """
         # allow async for
-        return _defined_names(self.children[self.children.index('for') + 1])
+        return _defined_names(self.children[1])
+
+
+# This is simply here so an older Jedi version can work with this new parso
+# version. Can be deleted in the next release.
+CompFor = SyncCompFor
+
+
+class UsedNamesMapping(Mapping):
+    """
+    This class exists for the sole purpose of creating an immutable dict.
+    """
+    def __init__(self, dct):
+        self._dict = dct
+
+    def __getitem__(self, key):
+        return self._dict[key]
+
+    def __len__(self):
+        return len(self._dict)
+
+    def __iter__(self):
+        return iter(self._dict)
+
+    def __hash__(self):
+        return id(self)
+
+    def __eq__(self, other):
+        # Comparing these dicts does not make sense.
+        return self is other

parso/utils.pyi

@@ -0,0 +1,29 @@
+from typing import NamedTuple, Optional, Sequence, Union
+
+class Version(NamedTuple):
+    major: int
+    minor: int
+    micro: int
+
+def split_lines(string: str, keepends: bool = ...) -> Sequence[str]: ...
+def python_bytes_to_unicode(
+    source: Union[str, bytes], encoding: str = ..., errors: str = ...
+) -> str: ...
+def version_info() -> Version:
+    """
+    Returns a namedtuple of parso's version, similar to Python's
+    ``sys.version_info``.
+    """
+    ...
+
+class PythonVersionInfo(NamedTuple):
+    major: int
+    minor: int
+
+def parse_version_string(version: Optional[str]) -> PythonVersionInfo:
+    """
+    Checks for a valid version number (e.g. `3.2` or `2.7.1` or `3`) and
+    returns a corresponding version info that is always two characters long in
+    decimal.
+    """
+    ...

test/failing_examples.py

@@ -146,7 +146,7 @@ FAILING_EXAMPLES = [
     # Now nested parsing
     "f'{continue}'",
     "f'{1;1}'",
-    "f'{a=3}'",
+    "f'{a;}'",
     "f'{b\"\" \"\"}'",
 ]
 

test/test_fstring.py

@@ -7,7 +7,7 @@ from parso.python.tokenize import tokenize
 
 @pytest.fixture
 def grammar():
-    return load_grammar(version='3.6')
+    return load_grammar(version='3.8')
 
 
 @pytest.mark.parametrize(
@@ -21,6 +21,9 @@ def grammar():
         '{1:1.{32}}',
         '{1::>4}',
         '{foo} {bar}',
+        '{x:{y}}',
+        '{x:{y:}}',
+        '{x:{y:1}}',
 
         # Escapes
         '{{}}',
@@ -28,6 +31,10 @@ def grammar():
         '{{{1}',
         '1{{2{{3',
         '}}',
+
+        # New Python 3.8 syntax f'{a=}'
+        '{a=}',
+        '{a()=}',
     ]
 )
 def test_valid(code, grammar):

test/test_parser.py

@@ -189,3 +189,22 @@ def test_no_error_nodes(each_version):
                 check(child)
 
     check(parse("if foo:\n bar", version=each_version))
+
+
+def test_named_expression(works_ge_py38):
+    works_ge_py38.parse("(a := 1, a + 1)")
+
+
+@pytest.mark.parametrize(
+    'param_code', [
+        'a=1, /',
+        'a, /',
+        'a=1, /, b=3',
+        'a, /, b',
+        'a, /, b',
+        'a, /, *, b',
+        'a, /, **kwargs',
+    ]
+)
+def test_positional_only_arguments(works_ge_py38, param_code):
+    works_ge_py38.parse("def x(%s): pass" % param_code)

test/test_pgen2.py

@@ -190,6 +190,19 @@ def test_old_octal_notation(works_in_py2):
     works_in_py2.parse("07")
 
 
+def test_long_notation(works_in_py2):
+    works_in_py2.parse("0xFl")
+    works_in_py2.parse("0xFL")
+    works_in_py2.parse("0b1l")
+    works_in_py2.parse("0B1L")
+    works_in_py2.parse("0o7l")
+    works_in_py2.parse("0O7L")
+    works_in_py2.parse("0l")
+    works_in_py2.parse("0L")
+    works_in_py2.parse("10l")
+    works_in_py2.parse("10L")
+
+
 def test_new_binary_notation(each_version):
     _parse("""0b101010""", each_version)
     _invalid_syntax("""0b0101021""", each_version)