# -*- coding: utf-8 -*- # Copyright (c) 2009-2011, 2013-2014 LOGILAB S.A. (Paris, FRANCE) # Copyright (c) 2010 Daniel Harding # Copyright (c) 2013-2016, 2018-2020 Claudiu Popa # Copyright (c) 2013-2014 Google, Inc. # Copyright (c) 2015-2016 Ceridwen # Copyright (c) 2016 Jared Garst # Copyright (c) 2016 Jakub Wilk # Copyright (c) 2017, 2019 Łukasz Rogalski # Copyright (c) 2017 rr- # Copyright (c) 2018 Serhiy Storchaka # Copyright (c) 2018 Ville Skyttä # Copyright (c) 2018 brendanator # Copyright (c) 2018 Nick Drozd # Copyright (c) 2019 Alex Hall # Copyright (c) 2019 Hugo van Kemenade # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html # For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER """This module renders Astroid nodes as string: * :func:`to_code` function return equivalent (hopefully valid) python string * :func:`dump` function return an internal representation of nodes found in the tree, useful for debugging or understanding the tree structure """ # pylint: disable=unused-argument DOC_NEWLINE = "\0" class AsStringVisitor: """Visitor to render an Astroid node as a valid python code string""" def __init__(self, indent): self.indent = indent def __call__(self, node): """Makes this visitor behave as a simple function""" return node.accept(self).replace(DOC_NEWLINE, "\n") def _docs_dedent(self, doc): """Stop newlines in docs being indented by self._stmt_list""" return '\n%s"""%s"""' % (self.indent, doc.replace("\n", DOC_NEWLINE)) def _stmt_list(self, stmts, indent=True): """return a list of nodes to string""" stmts = "\n".join(nstr for nstr in [n.accept(self) for n in stmts] if nstr) if indent: return self.indent + stmts.replace("\n", "\n" + self.indent) return stmts def _precedence_parens(self, node, child, is_left=True): """Wrap child in parens only if required to keep same semantics""" if self._should_wrap(node, child, is_left): return "(%s)" % child.accept(self) return child.accept(self) def _should_wrap(self, node, child, is_left): """Wrap child if: - it has lower precedence - same precedence with position opposite to associativity direction """ node_precedence = node.op_precedence() child_precedence = child.op_precedence() if node_precedence > child_precedence: # 3 * (4 + 5) return True if ( node_precedence == child_precedence and is_left != node.op_left_associative() ): # 3 - (4 - 5) # (2**3)**4 return True return False ## visit_ methods ########################################### def visit_await(self, node): return "await %s" % node.value.accept(self) def visit_asyncwith(self, node): return "async %s" % self.visit_with(node) def visit_asyncfor(self, node): return "async %s" % self.visit_for(node) def visit_arguments(self, node): """return an astroid.Function node as string""" return node.format_args() def visit_assignattr(self, node): """return an astroid.AssAttr node as string""" return self.visit_attribute(node) def visit_assert(self, node): """return an astroid.Assert node as string""" if node.fail: return "assert %s, %s" % (node.test.accept(self), node.fail.accept(self)) return "assert %s" % node.test.accept(self) def visit_assignname(self, node): """return an astroid.AssName node as string""" return node.name def visit_assign(self, node): """return an astroid.Assign node as string""" lhs = " = ".join(n.accept(self) for n in node.targets) return "%s = %s" % (lhs, node.value.accept(self)) def visit_augassign(self, node): """return an astroid.AugAssign node as string""" return "%s %s %s" % (node.target.accept(self), node.op, node.value.accept(self)) def visit_annassign(self, node): """Return an astroid.AugAssign node as string""" target = node.target.accept(self) annotation = node.annotation.accept(self) if node.value is None: return "%s: %s" % (target, annotation) return "%s: %s = %s" % (target, annotation, node.value.accept(self)) def visit_repr(self, node): """return an astroid.Repr node as string""" return "`%s`" % node.value.accept(self) def visit_binop(self, node): """return an astroid.BinOp node as string""" left = self._precedence_parens(node, node.left) right = self._precedence_parens(node, node.right, is_left=False) if node.op == "**": return "%s%s%s" % (left, node.op, right) return "%s %s %s" % (left, node.op, right) def visit_boolop(self, node): """return an astroid.BoolOp node as string""" values = ["%s" % self._precedence_parens(node, n) for n in node.values] return (" %s " % node.op).join(values) def visit_break(self, node): """return an astroid.Break node as string""" return "break" def visit_call(self, node): """return an astroid.Call node as string""" expr_str = self._precedence_parens(node, node.func) args = [arg.accept(self) for arg in node.args] if node.keywords: keywords = [kwarg.accept(self) for kwarg in node.keywords] else: keywords = [] args.extend(keywords) return "%s(%s)" % (expr_str, ", ".join(args)) def visit_classdef(self, node): """return an astroid.ClassDef node as string""" decorate = node.decorators.accept(self) if node.decorators else "" args = [n.accept(self) for n in node.bases] if node._metaclass and not node.has_metaclass_hack(): args.append("metaclass=" + node._metaclass.accept(self)) args += [n.accept(self) for n in node.keywords] args = "(%s)" % ", ".join(args) if args else "" docs = self._docs_dedent(node.doc) if node.doc else "" return "\n\n%sclass %s%s:%s\n%s\n" % ( decorate, node.name, args, docs, self._stmt_list(node.body), ) def visit_compare(self, node): """return an astroid.Compare node as string""" rhs_str = " ".join( [ "%s %s" % (op, self._precedence_parens(node, expr, is_left=False)) for op, expr in node.ops ] ) return "%s %s" % (self._precedence_parens(node, node.left), rhs_str) def visit_comprehension(self, node): """return an astroid.Comprehension node as string""" ifs = "".join(" if %s" % n.accept(self) for n in node.ifs) generated = "for %s in %s%s" % ( node.target.accept(self), node.iter.accept(self), ifs, ) return "%s%s" % ("async " if node.is_async else "", generated) def visit_const(self, node): """return an astroid.Const node as string""" if node.value is Ellipsis: return "..." return repr(node.value) def visit_continue(self, node): """return an astroid.Continue node as string""" return "continue" def visit_delete(self, node): # XXX check if correct """return an astroid.Delete node as string""" return "del %s" % ", ".join(child.accept(self) for child in node.targets) def visit_delattr(self, node): """return an astroid.DelAttr node as string""" return self.visit_attribute(node) def visit_delname(self, node): """return an astroid.DelName node as string""" return node.name def visit_decorators(self, node): """return an astroid.Decorators node as string""" return "@%s\n" % "\n@".join(item.accept(self) for item in node.nodes) def visit_dict(self, node): """return an astroid.Dict node as string""" return "{%s}" % ", ".join(self._visit_dict(node)) def _visit_dict(self, node): for key, value in node.items: key = key.accept(self) value = value.accept(self) if key == "**": # It can only be a DictUnpack node. yield key + value else: yield "%s: %s" % (key, value) def visit_dictunpack(self, node): return "**" def visit_dictcomp(self, node): """return an astroid.DictComp node as string""" return "{%s: %s %s}" % ( node.key.accept(self), node.value.accept(self), " ".join(n.accept(self) for n in node.generators), ) def visit_expr(self, node): """return an astroid.Discard node as string""" return node.value.accept(self) def visit_emptynode(self, node): """dummy method for visiting an Empty node""" return "" def visit_excepthandler(self, node): if node.type: if node.name: excs = "except %s as %s" % ( node.type.accept(self), node.name.accept(self), ) else: excs = "except %s" % node.type.accept(self) else: excs = "except" return "%s:\n%s" % (excs, self._stmt_list(node.body)) def visit_ellipsis(self, node): """return an astroid.Ellipsis node as string""" return "..." def visit_empty(self, node): """return an Empty node as string""" return "" def visit_exec(self, node): """return an astroid.Exec node as string""" if node.locals: return "exec %s in %s, %s" % ( node.expr.accept(self), node.locals.accept(self), node.globals.accept(self), ) if node.globals: return "exec %s in %s" % (node.expr.accept(self), node.globals.accept(self)) return "exec %s" % node.expr.accept(self) def visit_extslice(self, node): """return an astroid.ExtSlice node as string""" return ", ".join(dim.accept(self) for dim in node.dims) def visit_for(self, node): """return an astroid.For node as string""" fors = "for %s in %s:\n%s" % ( node.target.accept(self), node.iter.accept(self), self._stmt_list(node.body), ) if node.orelse: fors = "%s\nelse:\n%s" % (fors, self._stmt_list(node.orelse)) return fors def visit_importfrom(self, node): """return an astroid.ImportFrom node as string""" return "from %s import %s" % ( "." * (node.level or 0) + node.modname, _import_string(node.names), ) def visit_joinedstr(self, node): string = "".join( # Use repr on the string literal parts # to get proper escapes, e.g. \n, \\, \" # But strip the quotes off the ends # (they will always be one character: ' or ") repr(value.value)[1:-1] # Literal braces must be doubled to escape them .replace("{", "{{").replace("}", "}}") # Each value in values is either a string literal (Const) # or a FormattedValue if type(value).__name__ == "Const" else value.accept(self) for value in node.values ) # Try to find surrounding quotes that don't appear at all in the string. # Because the formatted values inside {} can't contain backslash (\) # using a triple quote is sometimes necessary for quote in ["'", '"', '"""', "'''"]: if quote not in string: break return "f" + quote + string + quote def visit_formattedvalue(self, node): result = node.value.accept(self) if node.conversion and node.conversion >= 0: # e.g. if node.conversion == 114: result += "!r" result += "!" + chr(node.conversion) if node.format_spec: # The format spec is itself a JoinedString, i.e. an f-string # We strip the f and quotes of the ends result += ":" + node.format_spec.accept(self)[2:-1] return "{%s}" % result def handle_functiondef(self, node, keyword): """return a (possibly async) function definition node as string""" decorate = node.decorators.accept(self) if node.decorators else "" docs = self._docs_dedent(node.doc) if node.doc else "" trailer = ":" if node.returns: return_annotation = " -> " + node.returns.as_string() trailer = return_annotation + ":" def_format = "\n%s%s %s(%s)%s%s\n%s" return def_format % ( decorate, keyword, node.name, node.args.accept(self), trailer, docs, self._stmt_list(node.body), ) def visit_functiondef(self, node): """return an astroid.FunctionDef node as string""" return self.handle_functiondef(node, "def") def visit_asyncfunctiondef(self, node): """return an astroid.AsyncFunction node as string""" return self.handle_functiondef(node, "async def") def visit_generatorexp(self, node): """return an astroid.GeneratorExp node as string""" return "(%s %s)" % ( node.elt.accept(self), " ".join(n.accept(self) for n in node.generators), ) def visit_attribute(self, node): """return an astroid.Getattr node as string""" left = self._precedence_parens(node, node.expr) if left.isdigit(): left = "(%s)" % left return "%s.%s" % (left, node.attrname) def visit_global(self, node): """return an astroid.Global node as string""" return "global %s" % ", ".join(node.names) def visit_if(self, node): """return an astroid.If node as string""" ifs = ["if %s:\n%s" % (node.test.accept(self), self._stmt_list(node.body))] if node.has_elif_block(): ifs.append("el%s" % self._stmt_list(node.orelse, indent=False)) elif node.orelse: ifs.append("else:\n%s" % self._stmt_list(node.orelse)) return "\n".join(ifs) def visit_ifexp(self, node): """return an astroid.IfExp node as string""" return "%s if %s else %s" % ( self._precedence_parens(node, node.body, is_left=True), self._precedence_parens(node, node.test, is_left=True), self._precedence_parens(node, node.orelse, is_left=False), ) def visit_import(self, node): """return an astroid.Import node as string""" return "import %s" % _import_string(node.names) def visit_keyword(self, node): """return an astroid.Keyword node as string""" if node.arg is None: return "**%s" % node.value.accept(self) return "%s=%s" % (node.arg, node.value.accept(self)) def visit_lambda(self, node): """return an astroid.Lambda node as string""" args = node.args.accept(self) body = node.body.accept(self) if args: return "lambda %s: %s" % (args, body) return "lambda: %s" % body def visit_list(self, node): """return an astroid.List node as string""" return "[%s]" % ", ".join(child.accept(self) for child in node.elts) def visit_listcomp(self, node): """return an astroid.ListComp node as string""" return "[%s %s]" % ( node.elt.accept(self), " ".join(n.accept(self) for n in node.generators), ) def visit_module(self, node): """return an astroid.Module node as string""" docs = '"""%s"""\n\n' % node.doc if node.doc else "" return docs + "\n".join(n.accept(self) for n in node.body) + "\n\n" def visit_name(self, node): """return an astroid.Name node as string""" return node.name def visit_namedexpr(self, node): """Return an assignment expression node as string""" target = node.target.accept(self) value = node.value.accept(self) return "%s := %s" % (target, value) def visit_nonlocal(self, node): """return an astroid.Nonlocal node as string""" return "nonlocal %s" % ", ".join(node.names) def visit_pass(self, node): """return an astroid.Pass node as string""" return "pass" def visit_print(self, node): """return an astroid.Print node as string""" nodes = ", ".join(n.accept(self) for n in node.values) if not node.nl: nodes = "%s," % nodes if node.dest: return "print >> %s, %s" % (node.dest.accept(self), nodes) return "print %s" % nodes def visit_raise(self, node): """return an astroid.Raise node as string""" if node.exc: if node.cause: return "raise %s from %s" % ( node.exc.accept(self), node.cause.accept(self), ) return "raise %s" % node.exc.accept(self) return "raise" def visit_return(self, node): """return an astroid.Return node as string""" if node.is_tuple_return() and len(node.value.elts) > 1: elts = [child.accept(self) for child in node.value.elts] return "return %s" % ", ".join(elts) if node.value: return "return %s" % node.value.accept(self) return "return" def visit_index(self, node): """return an astroid.Index node as string""" return node.value.accept(self) def visit_set(self, node): """return an astroid.Set node as string""" return "{%s}" % ", ".join(child.accept(self) for child in node.elts) def visit_setcomp(self, node): """return an astroid.SetComp node as string""" return "{%s %s}" % ( node.elt.accept(self), " ".join(n.accept(self) for n in node.generators), ) def visit_slice(self, node): """return an astroid.Slice node as string""" lower = node.lower.accept(self) if node.lower else "" upper = node.upper.accept(self) if node.upper else "" step = node.step.accept(self) if node.step else "" if step: return "%s:%s:%s" % (lower, upper, step) return "%s:%s" % (lower, upper) def visit_subscript(self, node): """return an astroid.Subscript node as string""" idx = node.slice if idx.__class__.__name__.lower() == "index": idx = idx.value idxstr = idx.accept(self) if idx.__class__.__name__.lower() == "tuple" and idx.elts: # Remove parenthesis in tuple and extended slice. # a[(::1, 1:)] is not valid syntax. idxstr = idxstr[1:-1] return "%s[%s]" % (self._precedence_parens(node, node.value), idxstr) def visit_tryexcept(self, node): """return an astroid.TryExcept node as string""" trys = ["try:\n%s" % self._stmt_list(node.body)] for handler in node.handlers: trys.append(handler.accept(self)) if node.orelse: trys.append("else:\n%s" % self._stmt_list(node.orelse)) return "\n".join(trys) def visit_tryfinally(self, node): """return an astroid.TryFinally node as string""" return "try:\n%s\nfinally:\n%s" % ( self._stmt_list(node.body), self._stmt_list(node.finalbody), ) def visit_tuple(self, node): """return an astroid.Tuple node as string""" if len(node.elts) == 1: return "(%s, )" % node.elts[0].accept(self) return "(%s)" % ", ".join(child.accept(self) for child in node.elts) def visit_unaryop(self, node): """return an astroid.UnaryOp node as string""" if node.op == "not": operator = "not " else: operator = node.op return "%s%s" % (operator, self._precedence_parens(node, node.operand)) def visit_while(self, node): """return an astroid.While node as string""" whiles = "while %s:\n%s" % (node.test.accept(self), self._stmt_list(node.body)) if node.orelse: whiles = "%s\nelse:\n%s" % (whiles, self._stmt_list(node.orelse)) return whiles def visit_with(self, node): # 'with' without 'as' is possible """return an astroid.With node as string""" items = ", ".join( ("%s" % expr.accept(self)) + (vars and " as %s" % (vars.accept(self)) or "") for expr, vars in node.items ) return "with %s:\n%s" % (items, self._stmt_list(node.body)) def visit_yield(self, node): """yield an ast.Yield node as string""" yi_val = (" " + node.value.accept(self)) if node.value else "" expr = "yield" + yi_val if node.parent.is_statement: return expr return "(%s)" % (expr,) def visit_yieldfrom(self, node): """ Return an astroid.YieldFrom node as string. """ yi_val = (" " + node.value.accept(self)) if node.value else "" expr = "yield from" + yi_val if node.parent.is_statement: return expr return "(%s)" % (expr,) def visit_starred(self, node): """return Starred node as string""" return "*" + node.value.accept(self) # These aren't for real AST nodes, but for inference objects. def visit_frozenset(self, node): return node.parent.accept(self) def visit_super(self, node): return node.parent.accept(self) def visit_uninferable(self, node): return str(node) def visit_property(self, node): return node.function.accept(self) def visit_evaluatedobject(self, node): return node.original.accept(self) def _import_string(names): """return a list of (name, asname) formatted as a string""" _names = [] for name, asname in names: if asname is not None: _names.append("%s as %s" % (name, asname)) else: _names.append(name) return ", ".join(_names) # This sets the default indent to 4 spaces. to_code = AsStringVisitor(" ")