1103 lines
38 KiB
Python
1103 lines
38 KiB
Python
# Code copied from Lib/ast.py from cpython 3.10 and slightly adjusted for gast
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#
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# PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
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# --------------------------------------------
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#
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# 1. This LICENSE AGREEMENT is between the Python Software Foundation
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# ("PSF"), and the Individual or Organization ("Licensee") accessing and
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# otherwise using this software ("Python") in source or binary form and
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# its associated documentation.
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#
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# 2. Subject to the terms and conditions of this License Agreement, PSF hereby
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# grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
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# analyze, test, perform and/or display publicly, prepare derivative works,
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# distribute, and otherwise use Python alone or in any derivative version,
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# provided, however, that PSF's License Agreement and PSF's notice of copyright,
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# i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
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# 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Python Software Foundation;
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# All Rights Reserved" are retained in Python alone or in any derivative version
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# prepared by Licensee.
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#
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# 3. In the event Licensee prepares a derivative work that is based on
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# or incorporates Python or any part thereof, and wants to make
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# the derivative work available to others as provided herein, then
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# Licensee hereby agrees to include in any such work a brief summary of
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# the changes made to Python.
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#
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# 4. PSF is making Python available to Licensee on an "AS IS"
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# basis. PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
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# IMPLIED. BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
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# DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
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# FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
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# INFRINGE ANY THIRD PARTY RIGHTS.
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#
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# 5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
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# FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
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# A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
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# OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
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#
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# 6. This License Agreement will automatically terminate upon a material
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# breach of its terms and conditions.
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#
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# 7. Nothing in this License Agreement shall be deemed to create any
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# relationship of agency, partnership, or joint venture between PSF and
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# Licensee. This License Agreement does not grant permission to use PSF
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# trademarks or trade name in a trademark sense to endorse or promote
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# products or services of Licensee, or any third party.
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#
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# 8. By copying, installing or otherwise using Python, Licensee
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# agrees to be bound by the terms and conditions of this License
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# Agreement.
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import sys
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from . import *
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from contextlib import contextmanager
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from string import printable
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class nullcontext(object):
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def __init__(self, enter_result=None):
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self.enter_result = enter_result
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def __enter__(self):
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return self.enter_result
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def __exit__(self, *excinfo):
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pass
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# Large float and imaginary literals get turned into infinities in the AST.
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# We unparse those infinities to INFSTR.
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_INFSTR = "1e" + repr(sys.float_info.max_10_exp + 1)
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class _Precedence(object):
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"""Precedence table that originated from python grammar."""
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TUPLE = 1
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YIELD = 2 # 'yield', 'yield from'
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TEST = 3 # 'if'-'else', 'lambda'
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OR = 4 # 'or'
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AND = 5 # 'and'
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NOT = 6 # 'not'
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CMP = 7 # '<', '>', '==', '>=', '<=', '!=',
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# 'in', 'not in', 'is', 'is not'
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EXPR = 8
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BOR = EXPR # '|'
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BXOR = 9 # '^'
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BAND = 10 # '&'
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SHIFT = 11 # '<<', '>>'
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ARITH = 12 # '+', '-'
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TERM = 13 # '*', '@', '/', '%', '//'
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FACTOR = 14 # unary '+', '-', '~'
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POWER = 15 # '**'
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AWAIT = 16 # 'await'
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ATOM = 17
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_SINGLE_QUOTES = ("'", '"')
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_MULTI_QUOTES = ('"""', "'''")
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_ALL_QUOTES = _SINGLE_QUOTES + _MULTI_QUOTES
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class _Unparser(NodeVisitor):
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"""Methods in this class recursively traverse an AST and
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output source code for the abstract syntax; original formatting
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is disregarded."""
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def __init__(self, _avoid_backslashes=False):
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self._source = []
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self._buffer = []
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self._precedences = {}
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self._type_ignores = {}
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self._indent = 0
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self._avoid_backslashes = _avoid_backslashes
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def interleave(self, inter, f, seq):
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"""Call f on each item in seq, calling inter() in between."""
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seq = iter(seq)
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try:
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f(next(seq))
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except StopIteration:
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pass
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else:
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for x in seq:
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inter()
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f(x)
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def items_view(self, traverser, items):
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"""Traverse and separate the given *items* with a comma and append it to
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the buffer. If *items* is a single item sequence, a trailing comma
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will be added."""
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if len(items) == 1:
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traverser(items[0])
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self.write(",")
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else:
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self.interleave(lambda: self.write(", "), traverser, items)
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def maybe_newline(self):
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"""Adds a newline if it isn't the start of generated source"""
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if self._source:
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self.write("\n")
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def fill(self, text=""):
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"""Indent a piece of text and append it, according to the current
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indentation level"""
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self.maybe_newline()
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self.write(" " * self._indent + text)
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def write(self, text):
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"""Append a piece of text"""
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self._source.append(text)
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def buffer_writer(self, text):
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self._buffer.append(text)
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@property
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def buffer(self):
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value = "".join(self._buffer)
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self._buffer.clear()
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return value
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@contextmanager
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def block(self, extra = None):
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"""A context manager for preparing the source for blocks. It adds
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the character':', increases the indentation on enter and decreases
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the indentation on exit. If *extra* is given, it will be directly
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appended after the colon character.
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"""
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self.write(":")
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if extra:
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self.write(extra)
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self._indent += 1
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yield
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self._indent -= 1
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@contextmanager
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def delimit(self, start, end):
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"""A context manager for preparing the source for expressions. It adds
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*start* to the buffer and enters, after exit it adds *end*."""
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self.write(start)
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yield
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self.write(end)
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def delimit_if(self, start, end, condition):
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if condition:
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return self.delimit(start, end)
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else:
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return nullcontext()
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def require_parens(self, precedence, node):
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"""Shortcut to adding precedence related parens"""
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return self.delimit_if("(", ")", self.get_precedence(node) > precedence)
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def get_precedence(self, node):
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return self._precedences.get(node, _Precedence.TEST)
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def set_precedence(self, precedence, *nodes):
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for node in nodes:
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self._precedences[node] = precedence
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def get_raw_docstring(self, node):
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"""If a docstring node is found in the body of the *node* parameter,
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return that docstring node, None otherwise.
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Logic mirrored from ``_PyAST_GetDocString``."""
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if not isinstance(
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node, (AsyncFunctionDef, FunctionDef, ClassDef, Module)
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) or len(node.body) < 1:
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return None
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node = node.body[0]
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if not isinstance(node, Expr):
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return None
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node = node.value
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if isinstance(node, Constant) and isinstance(node.value, str):
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return node
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def get_type_comment(self, node):
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comment = self._type_ignores.get(node.lineno) or node.type_comment
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if comment is not None:
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return " # type: {}".format(comment)
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def traverse(self, node):
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if isinstance(node, list):
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for item in node:
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self.traverse(item)
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else:
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super(_Unparser, self).visit(node)
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# Note: as visit() resets the output text, do NOT rely on
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# NodeVisitor.generic_visit to handle any nodes (as it calls back in to
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# the subclass visit() method, which resets self._source to an empty list)
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def visit(self, node):
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"""Outputs a source code string that, if converted back to an ast
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(using ast.parse) will generate an AST equivalent to *node*"""
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self._source = []
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self.traverse(node)
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return "".join(self._source)
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def _write_docstring_and_traverse_body(self, node):
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docstring = self.get_raw_docstring(node)
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if docstring:
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self._write_docstring(docstring)
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self.traverse(node.body[1:])
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else:
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self.traverse(node.body)
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def visit_Module(self, node):
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self._type_ignores = {
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ignore.lineno: "ignore{}".format(ignore.tag)
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for ignore in node.type_ignores
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}
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self._write_docstring_and_traverse_body(node)
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self._type_ignores.clear()
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def visit_FunctionType(self, node):
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with self.delimit("(", ")"):
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self.interleave(
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lambda: self.write(", "), self.traverse, node.argtypes
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)
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self.write(" -> ")
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self.traverse(node.returns)
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def visit_Expr(self, node):
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self.fill()
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self.set_precedence(_Precedence.YIELD, node.value)
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self.traverse(node.value)
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def visit_NamedExpr(self, node):
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with self.require_parens(_Precedence.TUPLE, node):
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self.set_precedence(_Precedence.ATOM, node.target, node.value)
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self.traverse(node.target)
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self.write(" := ")
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self.traverse(node.value)
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def visit_Import(self, node):
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self.fill("import ")
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self.interleave(lambda: self.write(", "), self.traverse, node.names)
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def visit_ImportFrom(self, node):
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self.fill("from ")
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self.write("." * node.level)
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if node.module:
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self.write(node.module)
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self.write(" import ")
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self.interleave(lambda: self.write(", "), self.traverse, node.names)
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def visit_Assign(self, node):
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self.fill()
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for target in node.targets:
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self.traverse(target)
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self.write(" = ")
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self.traverse(node.value)
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type_comment = self.get_type_comment(node)
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if type_comment:
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self.write(type_comment)
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def visit_AugAssign(self, node):
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self.fill()
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self.traverse(node.target)
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self.write(" " + self.binop[node.op.__class__.__name__] + "= ")
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self.traverse(node.value)
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def visit_AnnAssign(self, node):
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self.fill()
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with self.delimit_if("(", ")", not node.simple and isinstance(node.target, Name)):
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self.traverse(node.target)
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self.write(": ")
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self.traverse(node.annotation)
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if node.value:
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self.write(" = ")
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self.traverse(node.value)
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def visit_Return(self, node):
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self.fill("return")
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if node.value:
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self.write(" ")
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self.traverse(node.value)
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def visit_Pass(self, node):
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self.fill("pass")
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def visit_Break(self, node):
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self.fill("break")
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def visit_Continue(self, node):
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self.fill("continue")
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def visit_Delete(self, node):
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self.fill("del ")
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self.interleave(lambda: self.write(", "), self.traverse, node.targets)
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def visit_Assert(self, node):
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self.fill("assert ")
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self.traverse(node.test)
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if node.msg:
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self.write(", ")
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self.traverse(node.msg)
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def visit_Global(self, node):
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self.fill("global ")
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self.interleave(lambda: self.write(", "), self.write, node.names)
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def visit_Nonlocal(self, node):
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self.fill("nonlocal ")
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self.interleave(lambda: self.write(", "), self.write, node.names)
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def visit_Await(self, node):
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with self.require_parens(_Precedence.AWAIT, node):
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self.write("await")
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if node.value:
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self.write(" ")
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self.set_precedence(_Precedence.ATOM, node.value)
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self.traverse(node.value)
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def visit_Yield(self, node):
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with self.require_parens(_Precedence.YIELD, node):
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self.write("yield")
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if node.value:
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self.write(" ")
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self.set_precedence(_Precedence.ATOM, node.value)
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self.traverse(node.value)
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def visit_YieldFrom(self, node):
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with self.require_parens(_Precedence.YIELD, node):
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self.write("yield from ")
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if not node.value:
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raise ValueError("Node can't be used without a value attribute.")
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self.set_precedence(_Precedence.ATOM, node.value)
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self.traverse(node.value)
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def visit_Raise(self, node):
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self.fill("raise")
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if not node.exc:
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if node.cause:
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raise ValueError("Node can't use cause without an exception.")
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return
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self.write(" ")
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self.traverse(node.exc)
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if node.cause:
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self.write(" from ")
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self.traverse(node.cause)
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def visit_Try(self, node):
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self.fill("try")
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with self.block():
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self.traverse(node.body)
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for ex in node.handlers:
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self.traverse(ex)
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if node.orelse:
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self.fill("else")
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with self.block():
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self.traverse(node.orelse)
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if node.finalbody:
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self.fill("finally")
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with self.block():
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self.traverse(node.finalbody)
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def visit_ExceptHandler(self, node):
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self.fill("except")
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if node.type:
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self.write(" ")
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self.traverse(node.type)
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if node.name:
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self.write(" as ")
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self.write(node.name.id)
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with self.block():
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self.traverse(node.body)
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def visit_ClassDef(self, node):
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self.maybe_newline()
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for deco in node.decorator_list:
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self.fill("@")
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self.traverse(deco)
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self.fill("class " + node.name)
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with self.delimit_if("(", ")", condition = node.bases or node.keywords):
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comma = False
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for e in node.bases:
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if comma:
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self.write(", ")
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else:
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comma = True
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self.traverse(e)
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for e in node.keywords:
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if comma:
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self.write(", ")
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else:
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comma = True
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self.traverse(e)
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with self.block():
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self._write_docstring_and_traverse_body(node)
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def visit_FunctionDef(self, node):
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self._function_helper(node, "def")
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def visit_AsyncFunctionDef(self, node):
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self._function_helper(node, "async def")
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def _function_helper(self, node, fill_suffix):
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self.maybe_newline()
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for deco in node.decorator_list:
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self.fill("@")
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self.traverse(deco)
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def_str = fill_suffix + " " + node.name
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self.fill(def_str)
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with self.delimit("(", ")"):
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self.traverse(node.args)
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if node.returns:
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self.write(" -> ")
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self.traverse(node.returns)
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with self.block(extra=self.get_type_comment(node)):
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self._write_docstring_and_traverse_body(node)
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def visit_For(self, node):
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self._for_helper("for ", node)
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def visit_AsyncFor(self, node):
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self._for_helper("async for ", node)
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def _for_helper(self, fill, node):
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self.fill(fill)
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self.traverse(node.target)
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self.write(" in ")
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self.traverse(node.iter)
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with self.block(extra=self.get_type_comment(node)):
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self.traverse(node.body)
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if node.orelse:
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self.fill("else")
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with self.block():
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self.traverse(node.orelse)
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def visit_If(self, node):
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self.fill("if ")
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self.traverse(node.test)
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with self.block():
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self.traverse(node.body)
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# collapse nested ifs into equivalent elifs.
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while node.orelse and len(node.orelse) == 1 and isinstance(node.orelse[0], If):
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node = node.orelse[0]
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self.fill("elif ")
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self.traverse(node.test)
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with self.block():
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self.traverse(node.body)
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# final else
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if node.orelse:
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self.fill("else")
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with self.block():
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self.traverse(node.orelse)
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def visit_While(self, node):
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self.fill("while ")
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self.traverse(node.test)
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with self.block():
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self.traverse(node.body)
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if node.orelse:
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self.fill("else")
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with self.block():
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self.traverse(node.orelse)
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def visit_With(self, node):
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self.fill("with ")
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self.interleave(lambda: self.write(", "), self.traverse, node.items)
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with self.block(extra=self.get_type_comment(node)):
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self.traverse(node.body)
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def visit_AsyncWith(self, node):
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self.fill("async with ")
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self.interleave(lambda: self.write(", "), self.traverse, node.items)
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with self.block(extra=self.get_type_comment(node)):
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self.traverse(node.body)
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def _str_literal_helper(
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self, string, quote_types=_ALL_QUOTES, escape_special_whitespace=False
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):
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"""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 all(cc in printable for cc in c):
|
|
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("{0}{1}{0}".format(quote_type, string))
|
|
|
|
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("{0}{1}{0}".format(quote_type, value))
|
|
|
|
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 + 1, 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("!{}".format(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", "({0}-{0})".format(_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 Ellipsis:
|
|
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 + 1, 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 + 1, 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 + 1
|
|
right_precedence = operator_precedence
|
|
else:
|
|
left_precedence = operator_precedence
|
|
right_precedence = operator_precedence + 1
|
|
|
|
self.set_precedence(left_precedence, node.left)
|
|
self.traverse(node.left)
|
|
self.write(" {} ".format(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 + 1, 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):
|
|
operator_precedence[0] += 1
|
|
self.set_precedence(operator_precedence[0], node)
|
|
self.traverse(node)
|
|
|
|
with self.require_parens(operator_precedence[0], node):
|
|
s = " {} ".format(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.id)
|
|
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.id)
|
|
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.id)
|
|
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("*{}".format(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("**{}".format(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("{}=".format(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(" as {}".format(node.name))
|
|
|
|
def visit_MatchOr(self, node):
|
|
with self.require_parens(_Precedence.BOR, node):
|
|
self.set_precedence(_Precedence.BOR + 1, *node.patterns)
|
|
self.interleave(lambda: self.write(" | "), self.traverse, node.patterns)
|
|
|
|
def unparse(ast_obj):
|
|
unparser = _Unparser()
|
|
return unparser.visit(ast_obj)
|