Update prebuilt Clang to r416183b from Android.
https://android.googlesource.com/platform/prebuilts/clang/host/
linux-x86/+/06a71ddac05c22edb2d10b590e1769b3f8619bef
clang 12.0.5 (based on r416183b) from build 7284624.
Change-Id: I277a316abcf47307562d8b748b84870f31a72866
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/linux-x64/clang/python3/lib/python3.9/ast.py b/linux-x64/clang/python3/lib/python3.9/ast.py
new file mode 100644
index 0000000..ecd4895
--- /dev/null
+++ b/linux-x64/clang/python3/lib/python3.9/ast.py
@@ -0,0 +1,1592 @@
+"""
+ 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):
+ """
+ Safely evaluate an expression node or a string containing 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.
+ """
+ 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.
+ self.write(repr(value).replace("inf", _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 not node.elts:
+ raise ValueError("Set node should have at least one item")
+ with self.delimit("{", "}"):
+ self.interleave(lambda: self.write(", "), self.traverse, node.elts)
+
+ 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 parantheses can be safely
+ # omitted if there aren't any elements that explicitly requires
+ # parantheses (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()