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authormonster <monster@ydb.tech>2022-07-07 14:41:37 +0300
committermonster <monster@ydb.tech>2022-07-07 14:41:37 +0300
commit06e5c21a835c0e923506c4ff27929f34e00761c2 (patch)
tree75efcbc6854ef9bd476eb8bf00cc5c900da436a2 /contrib/tools/python3/src/Lib/ast.py
parent03f024c4412e3aa613bb543cf1660176320ba8f4 (diff)
downloadydb-06e5c21a835c0e923506c4ff27929f34e00761c2.tar.gz
fix ya.make
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-"""
- 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.lstrip(" \t"), mode='eval')
- if isinstance(node_or_string, Expression):
- node_or_string = node_or_string.body
- def _raise_malformed_node(node):
- msg = "malformed node or string"
- if lno := getattr(node, 'lineno', None):
- msg += f' on line {lno}'
- raise ValueError(msg + f': {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)
-
- # Note: as visit() resets the output text, do NOT rely on
- # NodeVisitor.generic_visit to handle any nodes (as it calls back in to
- # the subclass visit() method, which resets self._source to an empty list)
- 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_Match(self, node):
- self.fill("match ")
- self.traverse(node.subject)
- with self.block():
- for case in node.cases:
- self.traverse(case)
-
- 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 visit_match_case(self, node):
- self.fill("case ")
- self.traverse(node.pattern)
- if node.guard:
- self.write(" if ")
- self.traverse(node.guard)
- with self.block():
- self.traverse(node.body)
-
- def visit_MatchValue(self, node):
- self.traverse(node.value)
-
- def visit_MatchSingleton(self, node):
- self._write_constant(node.value)
-
- def visit_MatchSequence(self, node):
- with self.delimit("[", "]"):
- self.interleave(
- lambda: self.write(", "), self.traverse, node.patterns
- )
-
- def visit_MatchStar(self, node):
- name = node.name
- if name is None:
- name = "_"
- self.write(f"*{name}")
-
- def visit_MatchMapping(self, node):
- def write_key_pattern_pair(pair):
- k, p = pair
- self.traverse(k)
- self.write(": ")
- self.traverse(p)
-
- with self.delimit("{", "}"):
- keys = node.keys
- self.interleave(
- lambda: self.write(", "),
- write_key_pattern_pair,
- zip(keys, node.patterns, strict=True),
- )
- rest = node.rest
- if rest is not None:
- if keys:
- self.write(", ")
- self.write(f"**{rest}")
-
- def visit_MatchClass(self, node):
- self.set_precedence(_Precedence.ATOM, node.cls)
- self.traverse(node.cls)
- with self.delimit("(", ")"):
- patterns = node.patterns
- self.interleave(
- lambda: self.write(", "), self.traverse, patterns
- )
- attrs = node.kwd_attrs
- if attrs:
- def write_attr_pattern(pair):
- attr, pattern = pair
- self.write(f"{attr}=")
- self.traverse(pattern)
-
- if patterns:
- self.write(", ")
- self.interleave(
- lambda: self.write(", "),
- write_attr_pattern,
- zip(attrs, node.kwd_patterns, strict=True),
- )
-
- def visit_MatchAs(self, node):
- name = node.name
- pattern = node.pattern
- if name is None:
- self.write("_")
- elif pattern is None:
- self.write(node.name)
- else:
- with self.require_parens(_Precedence.TEST, node):
- self.set_precedence(_Precedence.BOR, node.pattern)
- self.traverse(node.pattern)
- self.write(f" as {node.name}")
-
- def visit_MatchOr(self, node):
- with self.require_parens(_Precedence.BOR, node):
- self.set_precedence(_Precedence.BOR.next(), *node.patterns)
- self.interleave(lambda: self.write(" | "), self.traverse, node.patterns)
-
-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()