FM / python3.9

/usr/lib64/python3.9

Name	Size	Mode	Actions
asyncio/	-	0755	rm
collections/	-	0755	rm
concurrent/	-	0755	rm
config-3.9-x86_64-linux-gnu/	-	0755	rm
ctypes/	-	0755	rm
curses/	-	0755	rm
dbm/	-	0755	rm
distutils/	-	0755	rm
email/	-	0755	rm
encodings/	-	0755	rm
ensurepip/	-	0755	rm
html/	-	0755	rm
http/	-	0755	rm
importlib/	-	0755	rm
json/	-	0755	rm
lib-dynload/	-	0755	rm
lib2to3/	-	0755	rm
logging/	-	0755	rm
multiprocessing/	-	0755	rm
pydoc_data/	-	0755	rm
site-packages/	-	0755	rm
sqlite3/	-	0755	rm
unittest/	-	0755	rm
urllib/	-	0755	rm
venv/	-	0755	rm
wsgiref/	-	0755	rm
xml/	-	0755	rm
xmlrpc/	-	0755	rm
zoneinfo/	-	0755	rm
__pycache__/	-	0755	rm
abc.py	4920	0644	edit dl rm
aifc.py	32605	0644	edit dl rm
antigravity.py	500	0644	edit dl rm
argparse.py	98119	0644	edit dl rm
ast.py	56256	0644	edit dl rm
asynchat.py	11321	0644	edit dl rm
asyncore.py	20102	0644	edit dl rm
base64.py	19859	0755	edit dl rm
bdb.py	31389	0644	edit dl rm
binhex.py	14784	0644	edit dl rm
bisect.py	2350	0644	edit dl rm
bz2.py	12447	0644	edit dl rm
calendar.py	24832	0644	edit dl rm
cgi.py	33932	0755	edit dl rm
cgitb.py	12096	0644	edit dl rm
chunk.py	5435	0644	edit dl rm
cmd.py	14860	0644	edit dl rm
code.py	10622	0644	edit dl rm
codecs.py	36673	0644	edit dl rm
codeop.py	6326	0644	edit dl rm
colorsys.py	4064	0644	edit dl rm
compileall.py	20105	0644	edit dl rm
configparser.py	54584	0644	edit dl rm
contextlib.py	24624	0644	edit dl rm
contextvars.py	129	0644	edit dl rm
copy.py	8650	0644	edit dl rm
copyreg.py	7274	0644	edit dl rm
cProfile.py	6345	0755	edit dl rm
crypt.py	3819	0644	edit dl rm
csv.py	16144	0644	edit dl rm
dataclasses.py	49586	0644	edit dl rm
datetime.py	89177	0644	edit dl rm
decimal.py	320	0644	edit dl rm
difflib.py	83307	0644	edit dl rm
dis.py	20570	0644	edit dl rm
doctest.py	104568	0644	edit dl rm
enum.py	39440	0644	edit dl rm
filecmp.py	10024	0644	edit dl rm
fileinput.py	14791	0644	edit dl rm
fnmatch.py	6004	0644	edit dl rm
formatter.py	15143	0644	edit dl rm
fractions.py	24323	0644	edit dl rm
ftplib.py	35496	0644	edit dl rm
functools.py	38881	0644	edit dl rm
genericpath.py	5246	0644	edit dl rm
getopt.py	7489	0644	edit dl rm
getpass.py	5990	0644	edit dl rm
gettext.py	27266	0644	edit dl rm
glob.py	5823	0644	edit dl rm
graphlib.py	9573	0644	edit dl rm
gzip.py	21772	0644	edit dl rm
hashlib.py	8069	0644	edit dl rm
heapq.py	22877	0644	edit dl rm
hmac.py	8043	0644	edit dl rm
imaplib.py	55256	0644	edit dl rm
imghdr.py	3808	0644	edit dl rm
imp.py	10536	0644	edit dl rm
inspect.py	118235	0644	edit dl rm
io.py	3541	0644	edit dl rm
ipaddress.py	80924	0644	edit dl rm
keyword.py	1047	0644	edit dl rm
LICENSE.txt	13937	0644	edit dl rm
linecache.py	5461	0644	edit dl rm
locale.py	78271	0644	edit dl rm
lzma.py	13231	0644	edit dl rm
mailbox.py	78794	0644	edit dl rm
mailcap.py	9116	0644	edit dl rm
mimetypes.py	21564	0644	edit dl rm
modulefinder.py	24401	0644	edit dl rm
netrc.py	5566	0644	edit dl rm
nntplib.py	41023	0644	edit dl rm
ntpath.py	26460	0644	edit dl rm
nturl2path.py	2887	0644	edit dl rm
numbers.py	10338	0644	edit dl rm
opcode.py	5660	0644	edit dl rm
operator.py	10751	0644	edit dl rm
optparse.py	60369	0644	edit dl rm
os.py	39065	0644	edit dl rm
pathlib.py	51134	0644	edit dl rm
pdb.py	63237	0755	edit dl rm
pickle.py	64920	0644	edit dl rm
pickletools.py	93486	0644	edit dl rm
pipes.py	8916	0644	edit dl rm
pkgutil.py	24276	0644	edit dl rm
platform.py	40601	0755	edit dl rm
plistlib.py	28248	0644	edit dl rm
poplib.py	15198	0644	edit dl rm
posixpath.py	16146	0644	edit dl rm
pprint.py	22527	0644	edit dl rm
profile.py	22881	0755	edit dl rm
pstats.py	29326	0644	edit dl rm
pty.py	4807	0644	edit dl rm
pyclbr.py	15255	0644	edit dl rm
pydoc.py	109599	0755	edit dl rm
py_compile.py	8203	0644	edit dl rm
queue.py	11496	0644	edit dl rm
quopri.py	7266	0755	edit dl rm
random.py	31484	0644	edit dl rm
re.py	15861	0644	edit dl rm
reprlib.py	5267	0644	edit dl rm
rlcompleter.py	7648	0644	edit dl rm
runpy.py	13084	0644	edit dl rm
sched.py	6442	0644	edit dl rm
secrets.py	2036	0644	edit dl rm
selectors.py	19536	0644	edit dl rm
shelve.py	8527	0644	edit dl rm
shlex.py	13501	0644	edit dl rm
shutil.py	53030	0644	edit dl rm
signal.py	2438	0644	edit dl rm
site.py	22085	0644	edit dl rm
smtpd.py	34821	0755	edit dl rm
smtplib.py	45405	0755	edit dl rm
sndhdr.py	7099	0644	edit dl rm
socket.py	36915	0644	edit dl rm
socketserver.py	27296	0644	edit dl rm
sre_compile.py	27973	0644	edit dl rm
sre_constants.py	7177	0644	edit dl rm
sre_parse.py	40779	0644	edit dl rm
ssl.py	52622	0644	edit dl rm
stat.py	5485	0644	edit dl rm
statistics.py	38067	0644	edit dl rm
string.py	10566	0644	edit dl rm
stringprep.py	12917	0644	edit dl rm
struct.py	257	0644	edit dl rm
subprocess.py	83564	0644	edit dl rm
sunau.py	18158	0644	edit dl rm
symbol.py	2281	0644	edit dl rm
symtable.py	7905	0644	edit dl rm
sysconfig.py	25557	0644	edit dl rm
tabnanny.py	11406	0755	edit dl rm
tarfile.py	112939	0755	edit dl rm
telnetlib.py	23254	0644	edit dl rm
tempfile.py	27963	0644	edit dl rm
textwrap.py	19407	0644	edit dl rm
this.py	1003	0644	edit dl rm
threading.py	54176	0644	edit dl rm
timeit.py	13480	0755	edit dl rm
token.py	2368	0644	edit dl rm
tokenize.py	25883	0644	edit dl rm
trace.py	29207	0755	edit dl rm
traceback.py	24660	0644	edit dl rm
tracemalloc.py	18047	0644	edit dl rm
tty.py	879	0644	edit dl rm
types.py	9785	0644	edit dl rm
typing.py	77044	0644	edit dl rm
uu.py	7277	0644	edit dl rm
uuid.py	27324	0644	edit dl rm
warnings.py	19688	0644	edit dl rm
wave.py	18004	0644	edit dl rm
weakref.py	21560	0644	edit dl rm
webbrowser.py	24083	0755	edit dl rm
xdrlib.py	5913	0644	edit dl rm
zipapp.py	7535	0644	edit dl rm
zipfile.py	88899	0644	edit dl rm
zipimport.py	30765	0644	edit dl rm
_aix_support.py	3389	0644	edit dl rm
_bootlocale.py	1801	0644	edit dl rm
_bootsubprocess.py	2675	0644	edit dl rm
_collections_abc.py	29374	0644	edit dl rm
_compat_pickle.py	8749	0644	edit dl rm
_compression.py	5340	0644	edit dl rm
_markupbase.py	14623	0644	edit dl rm
_osx_support.py	21773	0644	edit dl rm
_pydecimal.py	228666	0644	edit dl rm
_pyio.py	93316	0644	edit dl rm
_py_abc.py	6189	0644	edit dl rm
_sitebuiltins.py	3115	0644	edit dl rm
_strptime.py	25277	0644	edit dl rm
_sysconfigdata__linux_x86_64-linux-gnu.py	41236	0644	edit dl rm
_threading_local.py	7220	0644	edit dl rm
_weakrefset.py	5923	0644	edit dl rm
__future__.py	5147	0644	edit dl rm
__phello__.foo.py	64	0644	edit dl rm

Edit: /usr/lib64/python3.9/ast.py (56256B)

"""
    ast
    ~~~

The `ast` module helps Python applications to process trees of the Python
    abstract syntax grammar.  The abstract syntax itself might change with
    each Python release; this module helps to find out programmatically what
    the current grammar looks like and allows modifications of it.

An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as
    a flag to the `compile()` builtin function or by using the `parse()`
    function from this module.  The result will be a tree of objects whose
    classes all inherit from `ast.AST`.

A modified abstract syntax tree can be compiled into a Python code object
    using the built-in `compile()` function.

Additionally various helper functions are provided that make working with
    the trees simpler.  The main intention of the helper functions and this
    module in general is to provide an easy to use interface for libraries
    that work tightly with the python syntax (template engines for example).

:copyright: Copyright 2008 by Armin Ronacher.
    :license: Python License.
"""
import sys
from _ast import *
from contextlib import contextmanager, nullcontext
from enum import IntEnum, auto

def parse(source, filename='<unknown>', mode='exec', *,
          type_comments=False, feature_version=None):
    """
    Parse the source into an AST node.
    Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
    Pass type_comments=True to get back type comments where the syntax allows.
    """
    flags = PyCF_ONLY_AST
    if type_comments:
        flags |= PyCF_TYPE_COMMENTS
    if isinstance(feature_version, tuple):
        major, minor = feature_version  # Should be a 2-tuple.
        assert major == 3
        feature_version = minor
    elif feature_version is None:
        feature_version = -1
    # Else it should be an int giving the minor version for 3.x.
    return compile(source, filename, mode, flags,
                   _feature_version=feature_version)

def literal_eval(node_or_string):
    """
    Evaluate an expression node or a string containing only a Python
    expression.  The string or node provided may only consist of the following
    Python literal structures: strings, bytes, numbers, tuples, lists, dicts,
    sets, booleans, and None.

Caution: A complex expression can overflow the C stack and cause a crash.
    """
    if isinstance(node_or_string, str):
        node_or_string = parse(node_or_string, mode='eval')
    if isinstance(node_or_string, Expression):
        node_or_string = node_or_string.body
    def _raise_malformed_node(node):
        raise ValueError(f'malformed node or string: {node!r}')
    def _convert_num(node):
        if not isinstance(node, Constant) or type(node.value) not in (int, float, complex):
            _raise_malformed_node(node)
        return node.value
    def _convert_signed_num(node):
        if isinstance(node, UnaryOp) and isinstance(node.op, (UAdd, USub)):
            operand = _convert_num(node.operand)
            if isinstance(node.op, UAdd):
                return + operand
            else:
                return - operand
        return _convert_num(node)
    def _convert(node):
        if isinstance(node, Constant):
            return node.value
        elif isinstance(node, Tuple):
            return tuple(map(_convert, node.elts))
        elif isinstance(node, List):
            return list(map(_convert, node.elts))
        elif isinstance(node, Set):
            return set(map(_convert, node.elts))
        elif (isinstance(node, Call) and isinstance(node.func, Name) and
              node.func.id == 'set' and node.args == node.keywords == []):
            return set()
        elif isinstance(node, Dict):
            if len(node.keys) != len(node.values):
                _raise_malformed_node(node)
            return dict(zip(map(_convert, node.keys),
                            map(_convert, node.values)))
        elif isinstance(node, BinOp) and isinstance(node.op, (Add, Sub)):
            left = _convert_signed_num(node.left)
            right = _convert_num(node.right)
            if isinstance(left, (int, float)) and isinstance(right, complex):
                if isinstance(node.op, Add):
                    return left + right
                else:
                    return left - right
        return _convert_signed_num(node)
    return _convert(node_or_string)

def dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
    """
    Return a formatted dump of the tree in node.  This is mainly useful for
    debugging purposes.  If annotate_fields is true (by default),
    the returned string will show the names and the values for fields.
    If annotate_fields is false, the result string will be more compact by
    omitting unambiguous field names.  Attributes such as line
    numbers and column offsets are not dumped by default.  If this is wanted,
    include_attributes can be set to true.  If indent is a non-negative
    integer or string, then the tree will be pretty-printed with that indent
    level. None (the default) selects the single line representation.
    """
    def _format(node, level=0):
        if indent is not None:
            level += 1
            prefix = '\n' + indent * level
            sep = ',\n' + indent * level
        else:
            prefix = ''
            sep = ', '
        if isinstance(node, AST):
            cls = type(node)
            args = []
            allsimple = True
            keywords = annotate_fields
            for name in node._fields:
                try:
                    value = getattr(node, name)
                except AttributeError:
                    keywords = True
                    continue
                if value is None and getattr(cls, name, ...) is None:
                    keywords = True
                    continue
                value, simple = _format(value, level)
                allsimple = allsimple and simple
                if keywords:
                    args.append('%s=%s' % (name, value))
                else:
                    args.append(value)
            if include_attributes and node._attributes:
                for name in node._attributes:
                    try:
                        value = getattr(node, name)
                    except AttributeError:
                        continue
                    if value is None and getattr(cls, name, ...) is None:
                        continue
                    value, simple = _format(value, level)
                    allsimple = allsimple and simple
                    args.append('%s=%s' % (name, value))
            if allsimple and len(args) <= 3:
                return '%s(%s)' % (node.__class__.__name__, ', '.join(args)), not args
            return '%s(%s%s)' % (node.__class__.__name__, prefix, sep.join(args)), False
        elif isinstance(node, list):
            if not node:
                return '[]', True
            return '[%s%s]' % (prefix, sep.join(_format(x, level)[0] for x in node)), False
        return repr(node), True

if not isinstance(node, AST):
        raise TypeError('expected AST, got %r' % node.__class__.__name__)
    if indent is not None and not isinstance(indent, str):
        indent = ' ' * indent
    return _format(node)[0]

def copy_location(new_node, old_node):
    """
    Copy source location (`lineno`, `col_offset`, `end_lineno`, and `end_col_offset`
    attributes) from *old_node* to *new_node* if possible, and return *new_node*.
    """
    for attr in 'lineno', 'col_offset', 'end_lineno', 'end_col_offset':
        if attr in old_node._attributes and attr in new_node._attributes:
            value = getattr(old_node, attr, None)
            # end_lineno and end_col_offset are optional attributes, and they
            # should be copied whether the value is None or not.
            if value is not None or (
                hasattr(old_node, attr) and attr.startswith("end_")
            ):
                setattr(new_node, attr, value)
    return new_node

def fix_missing_locations(node):
    """
    When you compile a node tree with compile(), the compiler expects lineno and
    col_offset attributes for every node that supports them.  This is rather
    tedious to fill in for generated nodes, so this helper adds these attributes
    recursively where not already set, by setting them to the values of the
    parent node.  It works recursively starting at *node*.
    """
    def _fix(node, lineno, col_offset, end_lineno, end_col_offset):
        if 'lineno' in node._attributes:
            if not hasattr(node, 'lineno'):
                node.lineno = lineno
            else:
                lineno = node.lineno
        if 'end_lineno' in node._attributes:
            if getattr(node, 'end_lineno', None) is None:
                node.end_lineno = end_lineno
            else:
                end_lineno = node.end_lineno
        if 'col_offset' in node._attributes:
            if not hasattr(node, 'col_offset'):
                node.col_offset = col_offset
            else:
                col_offset = node.col_offset
        if 'end_col_offset' in node._attributes:
            if getattr(node, 'end_col_offset', None) is None:
                node.end_col_offset = end_col_offset
            else:
                end_col_offset = node.end_col_offset
        for child in iter_child_nodes(node):
            _fix(child, lineno, col_offset, end_lineno, end_col_offset)
    _fix(node, 1, 0, 1, 0)
    return node

def increment_lineno(node, n=1):
    """
    Increment the line number and end line number of each node in the tree
    starting at *node* by *n*. This is useful to "move code" to a different
    location in a file.
    """
    for child in walk(node):
        if 'lineno' in child._attributes:
            child.lineno = getattr(child, 'lineno', 0) + n
        if (
            "end_lineno" in child._attributes
            and (end_lineno := getattr(child, "end_lineno", 0)) is not None
        ):
            child.end_lineno = end_lineno + n
    return node

def iter_fields(node):
    """
    Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields``
    that is present on *node*.
    """
    for field in node._fields:
        try:
            yield field, getattr(node, field)
        except AttributeError:
            pass

def iter_child_nodes(node):
    """
    Yield all direct child nodes of *node*, that is, all fields that are nodes
    and all items of fields that are lists of nodes.
    """
    for name, field in iter_fields(node):
        if isinstance(field, AST):
            yield field
        elif isinstance(field, list):
            for item in field:
                if isinstance(item, AST):
                    yield item

def get_docstring(node, clean=True):
    """
    Return the docstring for the given node or None if no docstring can
    be found.  If the node provided does not have docstrings a TypeError
    will be raised.

If *clean* is `True`, all tabs are expanded to spaces and any whitespace
    that can be uniformly removed from the second line onwards is removed.
    """
    if not isinstance(node, (AsyncFunctionDef, FunctionDef, ClassDef, Module)):
        raise TypeError("%r can't have docstrings" % node.__class__.__name__)
    if not(node.body and isinstance(node.body[0], Expr)):
        return None
    node = node.body[0].value
    if isinstance(node, Str):
        text = node.s
    elif isinstance(node, Constant) and isinstance(node.value, str):
        text = node.value
    else:
        return None
    if clean:
        import inspect
        text = inspect.cleandoc(text)
    return text

def _splitlines_no_ff(source):
    """Split a string into lines ignoring form feed and other chars.

This mimics how the Python parser splits source code.
    """
    idx = 0
    lines = []
    next_line = ''
    while idx < len(source):
        c = source[idx]
        next_line += c
        idx += 1
        # Keep \r\n together
        if c == '\r' and idx < len(source) and source[idx] == '\n':
            next_line += '\n'
            idx += 1
        if c in '\r\n':
            lines.append(next_line)
            next_line = ''

if next_line:
        lines.append(next_line)
    return lines

def _pad_whitespace(source):
    r"""Replace all chars except '\f\t' in a line with spaces."""
    result = ''
    for c in source:
        if c in '\f\t':
            result += c
        else:
            result += ' '
    return result

def get_source_segment(source, node, *, padded=False):
    """Get source code segment of the *source* that generated *node*.

If some location information (`lineno`, `end_lineno`, `col_offset`,
    or `end_col_offset`) is missing, return None.

If *padded* is `True`, the first line of a multi-line statement will
    be padded with spaces to match its original position.
    """
    try:
        if node.end_lineno is None or node.end_col_offset is None:
            return None
        lineno = node.lineno - 1
        end_lineno = node.end_lineno - 1
        col_offset = node.col_offset
        end_col_offset = node.end_col_offset
    except AttributeError:
        return None

lines = _splitlines_no_ff(source)
    if end_lineno == lineno:
        return lines[lineno].encode()[col_offset:end_col_offset].decode()

if padded:
        padding = _pad_whitespace(lines[lineno].encode()[:col_offset].decode())
    else:
        padding = ''

first = padding + lines[lineno].encode()[col_offset:].decode()
    last = lines[end_lineno].encode()[:end_col_offset].decode()
    lines = lines[lineno+1:end_lineno]

lines.insert(0, first)
    lines.append(last)
    return ''.join(lines)

def walk(node):
    """
    Recursively yield all descendant nodes in the tree starting at *node*
    (including *node* itself), in no specified order.  This is useful if you
    only want to modify nodes in place and don't care about the context.
    """
    from collections import deque
    todo = deque([node])
    while todo:
        node = todo.popleft()
        todo.extend(iter_child_nodes(node))
        yield node

class NodeVisitor(object):
    """
    A node visitor base class that walks the abstract syntax tree and calls a
    visitor function for every node found.  This function may return a value
    which is forwarded by the `visit` method.

This class is meant to be subclassed, with the subclass adding visitor
    methods.

Per default the visitor functions for the nodes are ``'visit_'`` +
    class name of the node.  So a `TryFinally` node visit function would
    be `visit_TryFinally`.  This behavior can be changed by overriding
    the `visit` method.  If no visitor function exists for a node
    (return value `None`) the `generic_visit` visitor is used instead.

Don't use the `NodeVisitor` if you want to apply changes to nodes during
    traversing.  For this a special visitor exists (`NodeTransformer`) that
    allows modifications.
    """

def visit(self, node):
        """Visit a node."""
        method = 'visit_' + node.__class__.__name__
        visitor = getattr(self, method, self.generic_visit)
        return visitor(node)

def generic_visit(self, node):
        """Called if no explicit visitor function exists for a node."""
        for field, value in iter_fields(node):
            if isinstance(value, list):
                for item in value:
                    if isinstance(item, AST):
                        self.visit(item)
            elif isinstance(value, AST):
                self.visit(value)

def visit_Constant(self, node):
        value = node.value
        type_name = _const_node_type_names.get(type(value))
        if type_name is None:
            for cls, name in _const_node_type_names.items():
                if isinstance(value, cls):
                    type_name = name
                    break
        if type_name is not None:
            method = 'visit_' + type_name
            try:
                visitor = getattr(self, method)
            except AttributeError:
                pass
            else:
                import warnings
                warnings.warn(f"{method} is deprecated; add visit_Constant",
                              DeprecationWarning, 2)
                return visitor(node)
        return self.generic_visit(node)

class NodeTransformer(NodeVisitor):
    """
    A :class:`NodeVisitor` subclass that walks the abstract syntax tree and
    allows modification of nodes.

The `NodeTransformer` will walk the AST and use the return value of the
    visitor methods to replace or remove the old node.  If the return value of
    the visitor method is ``None``, the node will be removed from its location,
    otherwise it is replaced with the return value.  The return value may be the
    original node in which case no replacement takes place.

Here is an example transformer that rewrites all occurrences of name lookups
    (``foo``) to ``data['foo']``::

class RewriteName(NodeTransformer):

def visit_Name(self, node):
               return Subscript(
                   value=Name(id='data', ctx=Load()),
                   slice=Constant(value=node.id),
                   ctx=node.ctx
               )

Keep in mind that if the node you're operating on has child nodes you must
    either transform the child nodes yourself or call the :meth:`generic_visit`
    method for the node first.

For nodes that were part of a collection of statements (that applies to all
    statement nodes), the visitor may also return a list of nodes rather than
    just a single node.

Usually you use the transformer like this::

node = YourTransformer().visit(node)
    """

def generic_visit(self, node):
        for field, old_value in iter_fields(node):
            if isinstance(old_value, list):
                new_values = []
                for value in old_value:
                    if isinstance(value, AST):
                        value = self.visit(value)
                        if value is None:
                            continue
                        elif not isinstance(value, AST):
                            new_values.extend(value)
                            continue
                    new_values.append(value)
                old_value[:] = new_values
            elif isinstance(old_value, AST):
                new_node = self.visit(old_value)
                if new_node is None:
                    delattr(node, field)
                else:
                    setattr(node, field, new_node)
        return node

# If the ast module is loaded more than once, only add deprecated methods once
if not hasattr(Constant, 'n'):
    # The following code is for backward compatibility.
    # It will be removed in future.

def _getter(self):
        """Deprecated. Use value instead."""
        return self.value

def _setter(self, value):
        self.value = value

Constant.n = property(_getter, _setter)
    Constant.s = property(_getter, _setter)

class _ABC(type):

def __init__(cls, *args):
        cls.__doc__ = """Deprecated AST node class. Use ast.Constant instead"""

def __instancecheck__(cls, inst):
        if not isinstance(inst, Constant):
            return False
        if cls in _const_types:
            try:
                value = inst.value
            except AttributeError:
                return False
            else:
                return (
                    isinstance(value, _const_types[cls]) and
                    not isinstance(value, _const_types_not.get(cls, ()))
                )
        return type.__instancecheck__(cls, inst)

def _new(cls, *args, **kwargs):
    for key in kwargs:
        if key not in cls._fields:
            # arbitrary keyword arguments are accepted
            continue
        pos = cls._fields.index(key)
        if pos < len(args):
            raise TypeError(f"{cls.__name__} got multiple values for argument {key!r}")
    if cls in _const_types:
        return Constant(*args, **kwargs)
    return Constant.__new__(cls, *args, **kwargs)

class Num(Constant, metaclass=_ABC):
    _fields = ('n',)
    __new__ = _new

class Str(Constant, metaclass=_ABC):
    _fields = ('s',)
    __new__ = _new

class Bytes(Constant, metaclass=_ABC):
    _fields = ('s',)
    __new__ = _new

class NameConstant(Constant, metaclass=_ABC):
    __new__ = _new

class Ellipsis(Constant, metaclass=_ABC):
    _fields = ()

def __new__(cls, *args, **kwargs):
        if cls is Ellipsis:
            return Constant(..., *args, **kwargs)
        return Constant.__new__(cls, *args, **kwargs)

_const_types = {
    Num: (int, float, complex),
    Str: (str,),
    Bytes: (bytes,),
    NameConstant: (type(None), bool),
    Ellipsis: (type(...),),
}
_const_types_not = {
    Num: (bool,),
}

_const_node_type_names = {
    bool: 'NameConstant',  # should be before int
    type(None): 'NameConstant',
    int: 'Num',
    float: 'Num',
    complex: 'Num',
    str: 'Str',
    bytes: 'Bytes',
    type(...): 'Ellipsis',
}

class slice(AST):
    """Deprecated AST node class."""

class Index(slice):
    """Deprecated AST node class. Use the index value directly instead."""
    def __new__(cls, value, **kwargs):
        return value

class ExtSlice(slice):
    """Deprecated AST node class. Use ast.Tuple instead."""
    def __new__(cls, dims=(), **kwargs):
        return Tuple(list(dims), Load(), **kwargs)

# If the ast module is loaded more than once, only add deprecated methods once
if not hasattr(Tuple, 'dims'):
    # The following code is for backward compatibility.
    # It will be removed in future.

def _dims_getter(self):
        """Deprecated. Use elts instead."""
        return self.elts

def _dims_setter(self, value):
        self.elts = value

Tuple.dims = property(_dims_getter, _dims_setter)

class Suite(mod):
    """Deprecated AST node class.  Unused in Python 3."""

class AugLoad(expr_context):
    """Deprecated AST node class.  Unused in Python 3."""

class AugStore(expr_context):
    """Deprecated AST node class.  Unused in Python 3."""

class Param(expr_context):
    """Deprecated AST node class.  Unused in Python 3."""

# Large float and imaginary literals get turned into infinities in the AST.
# We unparse those infinities to INFSTR.
_INFSTR = "1e" + repr(sys.float_info.max_10_exp + 1)

class _Precedence(IntEnum):
    """Precedence table that originated from python grammar."""

TUPLE = auto()
    YIELD = auto()           # 'yield', 'yield from'
    TEST = auto()            # 'if'-'else', 'lambda'
    OR = auto()              # 'or'
    AND = auto()             # 'and'
    NOT = auto()             # 'not'
    CMP = auto()             # '<', '>', '==', '>=', '<=', '!=',
                             # 'in', 'not in', 'is', 'is not'
    EXPR = auto()
    BOR = EXPR               # '|'
    BXOR = auto()            # '^'
    BAND = auto()            # '&'
    SHIFT = auto()           # '<<', '>>'
    ARITH = auto()           # '+', '-'
    TERM = auto()            # '*', '@', '/', '%', '//'
    FACTOR = auto()          # unary '+', '-', '~'
    POWER = auto()           # '**'
    AWAIT = auto()           # 'await'
    ATOM = auto()

def next(self):
        try:
            return self.__class__(self + 1)
        except ValueError:
            return self

_SINGLE_QUOTES = ("'", '"')
_MULTI_QUOTES = ('"""', "'''")
_ALL_QUOTES = (*_SINGLE_QUOTES, *_MULTI_QUOTES)

class _Unparser(NodeVisitor):
    """Methods in this class recursively traverse an AST and
    output source code for the abstract syntax; original formatting
    is disregarded."""

def __init__(self, *, _avoid_backslashes=False):
        self._source = []
        self._buffer = []
        self._precedences = {}
        self._type_ignores = {}
        self._indent = 0
        self._avoid_backslashes = _avoid_backslashes

def interleave(self, inter, f, seq):
        """Call f on each item in seq, calling inter() in between."""
        seq = iter(seq)
        try:
            f(next(seq))
        except StopIteration:
            pass
        else:
            for x in seq:
                inter()
                f(x)

def items_view(self, traverser, items):
        """Traverse and separate the given *items* with a comma and append it to
        the buffer. If *items* is a single item sequence, a trailing comma
        will be added."""
        if len(items) == 1:
            traverser(items[0])
            self.write(",")
        else:
            self.interleave(lambda: self.write(", "), traverser, items)

def maybe_newline(self):
        """Adds a newline if it isn't the start of generated source"""
        if self._source:
            self.write("\n")

def fill(self, text=""):
        """Indent a piece of text and append it, according to the current
        indentation level"""
        self.maybe_newline()
        self.write("    " * self._indent + text)

def write(self, text):
        """Append a piece of text"""
        self._source.append(text)

def buffer_writer(self, text):
        self._buffer.append(text)

@property
    def buffer(self):
        value = "".join(self._buffer)
        self._buffer.clear()
        return value

@contextmanager
    def block(self, *, extra = None):
        """A context manager for preparing the source for blocks. It adds
        the character':', increases the indentation on enter and decreases
        the indentation on exit. If *extra* is given, it will be directly
        appended after the colon character.
        """
        self.write(":")
        if extra:
            self.write(extra)
        self._indent += 1
        yield
        self._indent -= 1

@contextmanager
    def delimit(self, start, end):
        """A context manager for preparing the source for expressions. It adds
        *start* to the buffer and enters, after exit it adds *end*."""

self.write(start)
        yield
        self.write(end)

def delimit_if(self, start, end, condition):
        if condition:
            return self.delimit(start, end)
        else:
            return nullcontext()

def require_parens(self, precedence, node):
        """Shortcut to adding precedence related parens"""
        return self.delimit_if("(", ")", self.get_precedence(node) > precedence)

def get_precedence(self, node):
        return self._precedences.get(node, _Precedence.TEST)

def set_precedence(self, precedence, *nodes):
        for node in nodes:
            self._precedences[node] = precedence

def get_raw_docstring(self, node):
        """If a docstring node is found in the body of the *node* parameter,
        return that docstring node, None otherwise.

Logic mirrored from ``_PyAST_GetDocString``."""
        if not isinstance(
            node, (AsyncFunctionDef, FunctionDef, ClassDef, Module)
        ) or len(node.body) < 1:
            return None
        node = node.body[0]
        if not isinstance(node, Expr):
            return None
        node = node.value
        if isinstance(node, Constant) and isinstance(node.value, str):
            return node

def get_type_comment(self, node):
        comment = self._type_ignores.get(node.lineno) or node.type_comment
        if comment is not None:
            return f" # type: {comment}"

def traverse(self, node):
        if isinstance(node, list):
            for item in node:
                self.traverse(item)
        else:
            super().visit(node)

def visit(self, node):
        """Outputs a source code string that, if converted back to an ast
        (using ast.parse) will generate an AST equivalent to *node*"""
        self._source = []
        self.traverse(node)
        return "".join(self._source)

def _write_docstring_and_traverse_body(self, node):
        if (docstring := self.get_raw_docstring(node)):
            self._write_docstring(docstring)
            self.traverse(node.body[1:])
        else:
            self.traverse(node.body)

def visit_Module(self, node):
        self._type_ignores = {
            ignore.lineno: f"ignore{ignore.tag}"
            for ignore in node.type_ignores
        }
        self._write_docstring_and_traverse_body(node)
        self._type_ignores.clear()

def visit_FunctionType(self, node):
        with self.delimit("(", ")"):
            self.interleave(
                lambda: self.write(", "), self.traverse, node.argtypes
            )

self.write(" -> ")
        self.traverse(node.returns)

def visit_Expr(self, node):
        self.fill()
        self.set_precedence(_Precedence.YIELD, node.value)
        self.traverse(node.value)

def visit_NamedExpr(self, node):
        with self.require_parens(_Precedence.TUPLE, node):
            self.set_precedence(_Precedence.ATOM, node.target, node.value)
            self.traverse(node.target)
            self.write(" := ")
            self.traverse(node.value)

def visit_Import(self, node):
        self.fill("import ")
        self.interleave(lambda: self.write(", "), self.traverse, node.names)

def visit_ImportFrom(self, node):
        self.fill("from ")
        self.write("." * node.level)
        if node.module:
            self.write(node.module)
        self.write(" import ")
        self.interleave(lambda: self.write(", "), self.traverse, node.names)

def visit_Assign(self, node):
        self.fill()
        for target in node.targets:
            self.traverse(target)
            self.write(" = ")
        self.traverse(node.value)
        if type_comment := self.get_type_comment(node):
            self.write(type_comment)

def visit_AugAssign(self, node):
        self.fill()
        self.traverse(node.target)
        self.write(" " + self.binop[node.op.__class__.__name__] + "= ")
        self.traverse(node.value)

def visit_AnnAssign(self, node):
        self.fill()
        with self.delimit_if("(", ")", not node.simple and isinstance(node.target, Name)):
            self.traverse(node.target)
        self.write(": ")
        self.traverse(node.annotation)
        if node.value:
            self.write(" = ")
            self.traverse(node.value)

def visit_Return(self, node):
        self.fill("return")
        if node.value:
            self.write(" ")
            self.traverse(node.value)

def visit_Pass(self, node):
        self.fill("pass")

def visit_Break(self, node):
        self.fill("break")

def visit_Continue(self, node):
        self.fill("continue")

def visit_Delete(self, node):
        self.fill("del ")
        self.interleave(lambda: self.write(", "), self.traverse, node.targets)

def visit_Assert(self, node):
        self.fill("assert ")
        self.traverse(node.test)
        if node.msg:
            self.write(", ")
            self.traverse(node.msg)

def visit_Global(self, node):
        self.fill("global ")
        self.interleave(lambda: self.write(", "), self.write, node.names)

def visit_Nonlocal(self, node):
        self.fill("nonlocal ")
        self.interleave(lambda: self.write(", "), self.write, node.names)

def visit_Await(self, node):
        with self.require_parens(_Precedence.AWAIT, node):
            self.write("await")
            if node.value:
                self.write(" ")
                self.set_precedence(_Precedence.ATOM, node.value)
                self.traverse(node.value)

def visit_Yield(self, node):
        with self.require_parens(_Precedence.YIELD, node):
            self.write("yield")
            if node.value:
                self.write(" ")
                self.set_precedence(_Precedence.ATOM, node.value)
                self.traverse(node.value)

def visit_YieldFrom(self, node):
        with self.require_parens(_Precedence.YIELD, node):
            self.write("yield from ")
            if not node.value:
                raise ValueError("Node can't be used without a value attribute.")
            self.set_precedence(_Precedence.ATOM, node.value)
            self.traverse(node.value)

def visit_Raise(self, node):
        self.fill("raise")
        if not node.exc:
            if node.cause:
                raise ValueError(f"Node can't use cause without an exception.")
            return
        self.write(" ")
        self.traverse(node.exc)
        if node.cause:
            self.write(" from ")
            self.traverse(node.cause)

def visit_Try(self, node):
        self.fill("try")
        with self.block():
            self.traverse(node.body)
        for ex in node.handlers:
            self.traverse(ex)
        if node.orelse:
            self.fill("else")
            with self.block():
                self.traverse(node.orelse)
        if node.finalbody:
            self.fill("finally")
            with self.block():
                self.traverse(node.finalbody)

def visit_ExceptHandler(self, node):
        self.fill("except")
        if node.type:
            self.write(" ")
            self.traverse(node.type)
        if node.name:
            self.write(" as ")
            self.write(node.name)
        with self.block():
            self.traverse(node.body)

def visit_ClassDef(self, node):
        self.maybe_newline()
        for deco in node.decorator_list:
            self.fill("@")
            self.traverse(deco)
        self.fill("class " + node.name)
        with self.delimit_if("(", ")", condition = node.bases or node.keywords):
            comma = False
            for e in node.bases:
                if comma:
                    self.write(", ")
                else:
                    comma = True
                self.traverse(e)
            for e in node.keywords:
                if comma:
                    self.write(", ")
                else:
                    comma = True
                self.traverse(e)

with self.block():
            self._write_docstring_and_traverse_body(node)

def visit_FunctionDef(self, node):
        self._function_helper(node, "def")

def visit_AsyncFunctionDef(self, node):
        self._function_helper(node, "async def")

def _function_helper(self, node, fill_suffix):
        self.maybe_newline()
        for deco in node.decorator_list:
            self.fill("@")
            self.traverse(deco)
        def_str = fill_suffix + " " + node.name
        self.fill(def_str)
        with self.delimit("(", ")"):
            self.traverse(node.args)
        if node.returns:
            self.write(" -> ")
            self.traverse(node.returns)
        with self.block(extra=self.get_type_comment(node)):
            self._write_docstring_and_traverse_body(node)

def visit_For(self, node):
        self._for_helper("for ", node)

def visit_AsyncFor(self, node):
        self._for_helper("async for ", node)

def _for_helper(self, fill, node):
        self.fill(fill)
        self.traverse(node.target)
        self.write(" in ")
        self.traverse(node.iter)
        with self.block(extra=self.get_type_comment(node)):
            self.traverse(node.body)
        if node.orelse:
            self.fill("else")
            with self.block():
                self.traverse(node.orelse)

def visit_If(self, node):
        self.fill("if ")
        self.traverse(node.test)
        with self.block():
            self.traverse(node.body)
        # collapse nested ifs into equivalent elifs.
        while node.orelse and len(node.orelse) == 1 and isinstance(node.orelse[0], If):
            node = node.orelse[0]
            self.fill("elif ")
            self.traverse(node.test)
            with self.block():
                self.traverse(node.body)
        # final else
        if node.orelse:
            self.fill("else")
            with self.block():
                self.traverse(node.orelse)

def visit_While(self, node):
        self.fill("while ")
        self.traverse(node.test)
        with self.block():
            self.traverse(node.body)
        if node.orelse:
            self.fill("else")
            with self.block():
                self.traverse(node.orelse)

def visit_With(self, node):
        self.fill("with ")
        self.interleave(lambda: self.write(", "), self.traverse, node.items)
        with self.block(extra=self.get_type_comment(node)):
            self.traverse(node.body)

def visit_AsyncWith(self, node):
        self.fill("async with ")
        self.interleave(lambda: self.write(", "), self.traverse, node.items)
        with self.block(extra=self.get_type_comment(node)):
            self.traverse(node.body)

def _str_literal_helper(
        self, string, *, quote_types=_ALL_QUOTES, escape_special_whitespace=False
    ):
        """Helper for writing string literals, minimizing escapes.
        Returns the tuple (string literal to write, possible quote types).
        """
        def escape_char(c):
            # \n and \t are non-printable, but we only escape them if
            # escape_special_whitespace is True
            if not escape_special_whitespace and c in "\n\t":
                return c
            # Always escape backslashes and other non-printable characters
            if c == "\\" or not c.isprintable():
                return c.encode("unicode_escape").decode("ascii")
            return c

escaped_string = "".join(map(escape_char, string))
        possible_quotes = quote_types
        if "\n" in escaped_string:
            possible_quotes = [q for q in possible_quotes if q in _MULTI_QUOTES]
        possible_quotes = [q for q in possible_quotes if q not in escaped_string]
        if not possible_quotes:
            # If there aren't any possible_quotes, fallback to using repr
            # on the original string. Try to use a quote from quote_types,
            # e.g., so that we use triple quotes for docstrings.
            string = repr(string)
            quote = next((q for q in quote_types if string[0] in q), string[0])
            return string[1:-1], [quote]
        if escaped_string:
            # Sort so that we prefer '''"''' over """\""""
            possible_quotes.sort(key=lambda q: q[0] == escaped_string[-1])
            # If we're using triple quotes and we'd need to escape a final
            # quote, escape it
            if possible_quotes[0][0] == escaped_string[-1]:
                assert len(possible_quotes[0]) == 3
                escaped_string = escaped_string[:-1] + "\\" + escaped_string[-1]
        return escaped_string, possible_quotes

def _write_str_avoiding_backslashes(self, string, *, quote_types=_ALL_QUOTES):
        """Write string literal value with a best effort attempt to avoid backslashes."""
        string, quote_types = self._str_literal_helper(string, quote_types=quote_types)
        quote_type = quote_types[0]
        self.write(f"{quote_type}{string}{quote_type}")

def visit_JoinedStr(self, node):
        self.write("f")
        if self._avoid_backslashes:
            self._fstring_JoinedStr(node, self.buffer_writer)
            self._write_str_avoiding_backslashes(self.buffer)
            return

# If we don't need to avoid backslashes globally (i.e., we only need
        # to avoid them inside FormattedValues), it's cosmetically preferred
        # to use escaped whitespace. That is, it's preferred to use backslashes
        # for cases like: f"{x}\n". To accomplish this, we keep track of what
        # in our buffer corresponds to FormattedValues and what corresponds to
        # Constant parts of the f-string, and allow escapes accordingly.
        buffer = []
        for value in node.values:
            meth = getattr(self, "_fstring_" + type(value).__name__)
            meth(value, self.buffer_writer)
            buffer.append((self.buffer, isinstance(value, Constant)))
        new_buffer = []
        quote_types = _ALL_QUOTES
        for value, is_constant in buffer:
            # Repeatedly narrow down the list of possible quote_types
            value, quote_types = self._str_literal_helper(
                value, quote_types=quote_types,
                escape_special_whitespace=is_constant
            )
            new_buffer.append(value)
        value = "".join(new_buffer)
        quote_type = quote_types[0]
        self.write(f"{quote_type}{value}{quote_type}")

def visit_FormattedValue(self, node):
        self.write("f")
        self._fstring_FormattedValue(node, self.buffer_writer)
        self._write_str_avoiding_backslashes(self.buffer)

def _fstring_JoinedStr(self, node, write):
        for value in node.values:
            meth = getattr(self, "_fstring_" + type(value).__name__)
            meth(value, write)

def _fstring_Constant(self, node, write):
        if not isinstance(node.value, str):
            raise ValueError("Constants inside JoinedStr should be a string.")
        value = node.value.replace("{", "{{").replace("}", "}}")
        write(value)

def _fstring_FormattedValue(self, node, write):
        write("{")
        unparser = type(self)(_avoid_backslashes=True)
        unparser.set_precedence(_Precedence.TEST.next(), node.value)
        expr = unparser.visit(node.value)
        if expr.startswith("{"):
            write(" ")  # Separate pair of opening brackets as "{ {"
        if "\\" in expr:
            raise ValueError("Unable to avoid backslash in f-string expression part")
        write(expr)
        if node.conversion != -1:
            conversion = chr(node.conversion)
            if conversion not in "sra":
                raise ValueError("Unknown f-string conversion.")
            write(f"!{conversion}")
        if node.format_spec:
            write(":")
            meth = getattr(self, "_fstring_" + type(node.format_spec).__name__)
            meth(node.format_spec, write)
        write("}")

def visit_Name(self, node):
        self.write(node.id)

def _write_docstring(self, node):
        self.fill()
        if node.kind == "u":
            self.write("u")
        self._write_str_avoiding_backslashes(node.value, quote_types=_MULTI_QUOTES)

def _write_constant(self, value):
        if isinstance(value, (float, complex)):
            # Substitute overflowing decimal literal for AST infinities,
            # and inf - inf for NaNs.
            self.write(
                repr(value)
                .replace("inf", _INFSTR)
                .replace("nan", f"({_INFSTR}-{_INFSTR})")
            )
        elif self._avoid_backslashes and isinstance(value, str):
            self._write_str_avoiding_backslashes(value)
        else:
            self.write(repr(value))

def visit_Constant(self, node):
        value = node.value
        if isinstance(value, tuple):
            with self.delimit("(", ")"):
                self.items_view(self._write_constant, value)
        elif value is ...:
            self.write("...")
        else:
            if node.kind == "u":
                self.write("u")
            self._write_constant(node.value)

def visit_List(self, node):
        with self.delimit("[", "]"):
            self.interleave(lambda: self.write(", "), self.traverse, node.elts)

def visit_ListComp(self, node):
        with self.delimit("[", "]"):
            self.traverse(node.elt)
            for gen in node.generators:
                self.traverse(gen)

def visit_GeneratorExp(self, node):
        with self.delimit("(", ")"):
            self.traverse(node.elt)
            for gen in node.generators:
                self.traverse(gen)

def visit_SetComp(self, node):
        with self.delimit("{", "}"):
            self.traverse(node.elt)
            for gen in node.generators:
                self.traverse(gen)

def visit_DictComp(self, node):
        with self.delimit("{", "}"):
            self.traverse(node.key)
            self.write(": ")
            self.traverse(node.value)
            for gen in node.generators:
                self.traverse(gen)

def visit_comprehension(self, node):
        if node.is_async:
            self.write(" async for ")
        else:
            self.write(" for ")
        self.set_precedence(_Precedence.TUPLE, node.target)
        self.traverse(node.target)
        self.write(" in ")
        self.set_precedence(_Precedence.TEST.next(), node.iter, *node.ifs)
        self.traverse(node.iter)
        for if_clause in node.ifs:
            self.write(" if ")
            self.traverse(if_clause)

def visit_IfExp(self, node):
        with self.require_parens(_Precedence.TEST, node):
            self.set_precedence(_Precedence.TEST.next(), node.body, node.test)
            self.traverse(node.body)
            self.write(" if ")
            self.traverse(node.test)
            self.write(" else ")
            self.set_precedence(_Precedence.TEST, node.orelse)
            self.traverse(node.orelse)

def visit_Set(self, node):
        if node.elts:
            with self.delimit("{", "}"):
                self.interleave(lambda: self.write(", "), self.traverse, node.elts)
        else:
            # `{}` would be interpreted as a dictionary literal, and
            # `set` might be shadowed. Thus:
            self.write('{*()}')

def visit_Dict(self, node):
        def write_key_value_pair(k, v):
            self.traverse(k)
            self.write(": ")
            self.traverse(v)

def write_item(item):
            k, v = item
            if k is None:
                # for dictionary unpacking operator in dicts {**{'y': 2}}
                # see PEP 448 for details
                self.write("**")
                self.set_precedence(_Precedence.EXPR, v)
                self.traverse(v)
            else:
                write_key_value_pair(k, v)

with self.delimit("{", "}"):
            self.interleave(
                lambda: self.write(", "), write_item, zip(node.keys, node.values)
            )

def visit_Tuple(self, node):
        with self.delimit("(", ")"):
            self.items_view(self.traverse, node.elts)

unop = {"Invert": "~", "Not": "not", "UAdd": "+", "USub": "-"}
    unop_precedence = {
        "not": _Precedence.NOT,
        "~": _Precedence.FACTOR,
        "+": _Precedence.FACTOR,
        "-": _Precedence.FACTOR,
    }

def visit_UnaryOp(self, node):
        operator = self.unop[node.op.__class__.__name__]
        operator_precedence = self.unop_precedence[operator]
        with self.require_parens(operator_precedence, node):
            self.write(operator)
            # factor prefixes (+, -, ~) shouldn't be seperated
            # from the value they belong, (e.g: +1 instead of + 1)
            if operator_precedence is not _Precedence.FACTOR:
                self.write(" ")
            self.set_precedence(operator_precedence, node.operand)
            self.traverse(node.operand)

binop = {
        "Add": "+",
        "Sub": "-",
        "Mult": "*",
        "MatMult": "@",
        "Div": "/",
        "Mod": "%",
        "LShift": "<<",
        "RShift": ">>",
        "BitOr": "|",
        "BitXor": "^",
        "BitAnd": "&",
        "FloorDiv": "//",
        "Pow": "**",
    }

binop_precedence = {
        "+": _Precedence.ARITH,
        "-": _Precedence.ARITH,
        "*": _Precedence.TERM,
        "@": _Precedence.TERM,
        "/": _Precedence.TERM,
        "%": _Precedence.TERM,
        "<<": _Precedence.SHIFT,
        ">>": _Precedence.SHIFT,
        "|": _Precedence.BOR,
        "^": _Precedence.BXOR,
        "&": _Precedence.BAND,
        "//": _Precedence.TERM,
        "**": _Precedence.POWER,
    }

binop_rassoc = frozenset(("**",))
    def visit_BinOp(self, node):
        operator = self.binop[node.op.__class__.__name__]
        operator_precedence = self.binop_precedence[operator]
        with self.require_parens(operator_precedence, node):
            if operator in self.binop_rassoc:
                left_precedence = operator_precedence.next()
                right_precedence = operator_precedence
            else:
                left_precedence = operator_precedence
                right_precedence = operator_precedence.next()

self.set_precedence(left_precedence, node.left)
            self.traverse(node.left)
            self.write(f" {operator} ")
            self.set_precedence(right_precedence, node.right)
            self.traverse(node.right)

cmpops = {
        "Eq": "==",
        "NotEq": "!=",
        "Lt": "<",
        "LtE": "<=",
        "Gt": ">",
        "GtE": ">=",
        "Is": "is",
        "IsNot": "is not",
        "In": "in",
        "NotIn": "not in",
    }

def visit_Compare(self, node):
        with self.require_parens(_Precedence.CMP, node):
            self.set_precedence(_Precedence.CMP.next(), node.left, *node.comparators)
            self.traverse(node.left)
            for o, e in zip(node.ops, node.comparators):
                self.write(" " + self.cmpops[o.__class__.__name__] + " ")
                self.traverse(e)

boolops = {"And": "and", "Or": "or"}
    boolop_precedence = {"and": _Precedence.AND, "or": _Precedence.OR}

def visit_BoolOp(self, node):
        operator = self.boolops[node.op.__class__.__name__]
        operator_precedence = self.boolop_precedence[operator]

def increasing_level_traverse(node):
            nonlocal operator_precedence
            operator_precedence = operator_precedence.next()
            self.set_precedence(operator_precedence, node)
            self.traverse(node)

with self.require_parens(operator_precedence, node):
            s = f" {operator} "
            self.interleave(lambda: self.write(s), increasing_level_traverse, node.values)

def visit_Attribute(self, node):
        self.set_precedence(_Precedence.ATOM, node.value)
        self.traverse(node.value)
        # Special case: 3.__abs__() is a syntax error, so if node.value
        # is an integer literal then we need to either parenthesize
        # it or add an extra space to get 3 .__abs__().
        if isinstance(node.value, Constant) and isinstance(node.value.value, int):
            self.write(" ")
        self.write(".")
        self.write(node.attr)

def visit_Call(self, node):
        self.set_precedence(_Precedence.ATOM, node.func)
        self.traverse(node.func)
        with self.delimit("(", ")"):
            comma = False
            for e in node.args:
                if comma:
                    self.write(", ")
                else:
                    comma = True
                self.traverse(e)
            for e in node.keywords:
                if comma:
                    self.write(", ")
                else:
                    comma = True
                self.traverse(e)

def visit_Subscript(self, node):
        def is_simple_tuple(slice_value):
            # when unparsing a non-empty tuple, the parentheses can be safely
            # omitted if there aren't any elements that explicitly requires
            # parentheses (such as starred expressions).
            return (
                isinstance(slice_value, Tuple)
                and slice_value.elts
                and not any(isinstance(elt, Starred) for elt in slice_value.elts)
            )

self.set_precedence(_Precedence.ATOM, node.value)
        self.traverse(node.value)
        with self.delimit("[", "]"):
            if is_simple_tuple(node.slice):
                self.items_view(self.traverse, node.slice.elts)
            else:
                self.traverse(node.slice)

def visit_Starred(self, node):
        self.write("*")
        self.set_precedence(_Precedence.EXPR, node.value)
        self.traverse(node.value)

def visit_Ellipsis(self, node):
        self.write("...")

def visit_Slice(self, node):
        if node.lower:
            self.traverse(node.lower)
        self.write(":")
        if node.upper:
            self.traverse(node.upper)
        if node.step:
            self.write(":")
            self.traverse(node.step)

def visit_arg(self, node):
        self.write(node.arg)
        if node.annotation:
            self.write(": ")
            self.traverse(node.annotation)

def visit_arguments(self, node):
        first = True
        # normal arguments
        all_args = node.posonlyargs + node.args
        defaults = [None] * (len(all_args) - len(node.defaults)) + node.defaults
        for index, elements in enumerate(zip(all_args, defaults), 1):
            a, d = elements
            if first:
                first = False
            else:
                self.write(", ")
            self.traverse(a)
            if d:
                self.write("=")
                self.traverse(d)
            if index == len(node.posonlyargs):
                self.write(", /")

# varargs, or bare '*' if no varargs but keyword-only arguments present
        if node.vararg or node.kwonlyargs:
            if first:
                first = False
            else:
                self.write(", ")
            self.write("*")
            if node.vararg:
                self.write(node.vararg.arg)
                if node.vararg.annotation:
                    self.write(": ")
                    self.traverse(node.vararg.annotation)

# keyword-only arguments
        if node.kwonlyargs:
            for a, d in zip(node.kwonlyargs, node.kw_defaults):
                self.write(", ")
                self.traverse(a)
                if d:
                    self.write("=")
                    self.traverse(d)

# kwargs
        if node.kwarg:
            if first:
                first = False
            else:
                self.write(", ")
            self.write("**" + node.kwarg.arg)
            if node.kwarg.annotation:
                self.write(": ")
                self.traverse(node.kwarg.annotation)

def visit_keyword(self, node):
        if node.arg is None:
            self.write("**")
        else:
            self.write(node.arg)
            self.write("=")
        self.traverse(node.value)

def visit_Lambda(self, node):
        with self.require_parens(_Precedence.TEST, node):
            self.write("lambda ")
            self.traverse(node.args)
            self.write(": ")
            self.set_precedence(_Precedence.TEST, node.body)
            self.traverse(node.body)

def visit_alias(self, node):
        self.write(node.name)
        if node.asname:
            self.write(" as " + node.asname)

def visit_withitem(self, node):
        self.traverse(node.context_expr)
        if node.optional_vars:
            self.write(" as ")
            self.traverse(node.optional_vars)

def unparse(ast_obj):
    unparser = _Unparser()
    return unparser.visit(ast_obj)

def main():
    import argparse

parser = argparse.ArgumentParser(prog='python -m ast')
    parser.add_argument('infile', type=argparse.FileType(mode='rb'), nargs='?',
                        default='-',
                        help='the file to parse; defaults to stdin')
    parser.add_argument('-m', '--mode', default='exec',
                        choices=('exec', 'single', 'eval', 'func_type'),
                        help='specify what kind of code must be parsed')
    parser.add_argument('--no-type-comments', default=True, action='store_false',
                        help="don't add information about type comments")
    parser.add_argument('-a', '--include-attributes', action='store_true',
                        help='include attributes such as line numbers and '
                             'column offsets')
    parser.add_argument('-i', '--indent', type=int, default=3,
                        help='indentation of nodes (number of spaces)')
    args = parser.parse_args()

with args.infile as infile:
        source = infile.read()
    tree = parse(source, args.infile.name, args.mode, type_comments=args.no_type_comments)
    print(dump(tree, include_attributes=args.include_attributes, indent=args.indent))

if __name__ == '__main__':
    main()

cmd: