# copyright 2003-2013 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:[email protected]
#
# This file is part of astroid.
#
# astroid is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by the
# Free Software Foundation, either version 2.1 of the License, or (at your
# option) any later version.
#
# astroid is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
# for more details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with astroid. If not, see <http://www.gnu.org/licenses/>.
"""This module renders Astroid nodes as string:
* :func:`to_code` function return equivalent (hopefuly valid) python string
* :func:`dump` function return an internal representation of nodes found
in the tree, useful for debugging or understanding the tree structure
"""
import sys
INDENT = ' ' # 4 spaces ; keep indentation variable
def dump(node, ids=False):
"""print a nice astroid tree representation.
:param ids: if true, we also print the ids (usefull for debugging)
"""
result = []
_repr_tree(node, result, ids=ids)
return "\n".join(result)
def _repr_tree(node, result, indent='', _done=None, ids=False):
"""built a tree representation of a node as a list of lines"""
if _done is None:
_done = set()
if not hasattr(node, '_astroid_fields'): # not a astroid node
return
if node in _done:
result.append(indent + 'loop in tree: %s' % node)
return
_done.add(node)
node_str = str(node)
if ids:
node_str += ' . \t%x' % id(node)
result.append(indent + node_str)
indent += INDENT
for field in node._astroid_fields:
value = getattr(node, field)
if isinstance(value, (list, tuple)):
result.append(indent + field + " = [")
for child in value:
if isinstance(child, (list, tuple)):
# special case for Dict # FIXME
_repr_tree(child[0], result, indent, _done, ids)
_repr_tree(child[1], result, indent, _done, ids)
result.append(indent + ',')
else:
_repr_tree(child, result, indent, _done, ids)
result.append(indent + "]")
else:
result.append(indent + field + " = ")
_repr_tree(value, result, indent, _done, ids)
class AsStringVisitor(object):
"""Visitor to render an Astroid node as a valid python code string"""
def __call__(self, node):
"""Makes this visitor behave as a simple function"""
return node.accept(self)
def _stmt_list(self, stmts):
"""return a list of nodes to string"""
stmts = '\n'.join([nstr for nstr in [n.accept(self) for n in stmts] if nstr])
return INDENT + stmts.replace('\n', '\n'+INDENT)
## visit_<node> methods ###########################################
def visit_arguments(self, node):
"""return an astroid.Function node as string"""
return node.format_args()
def visit_assattr(self, node):
"""return an astroid.AssAttr node as string"""
return self.visit_getattr(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_assname(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_backquote(self, node):
"""return an astroid.Backquote node as string"""
return '`%s`' % node.value.accept(self)
def visit_binop(self, node):
"""return an astroid.BinOp node as string"""
return '(%s) %s (%s)' % (node.left.accept(self), node.op, node.right.accept(self))
def visit_boolop(self, node):
"""return an astroid.BoolOp node as string"""
return (' %s ' % node.op).join(['(%s)' % n.accept(self)
for n in node.values])
def visit_break(self, node):
"""return an astroid.Break node as string"""
return 'break'
def visit_callfunc(self, node):
"""return an astroid.CallFunc node as string"""
expr_str = node.func.accept(self)
args = [arg.accept(self) for arg in node.args]
if node.starargs:
args.append('*' + node.starargs.accept(self))
if node.kwargs:
args.append('**' + node.kwargs.accept(self))
return '%s(%s)' % (expr_str, ', '.join(args))
def visit_class(self, node):
"""return an astroid.Class node as string"""
decorate = node.decorators and node.decorators.accept(self) or ''
bases = ', '.join([n.accept(self) for n in node.bases])
if sys.version_info[0] == 2:
bases = bases and '(%s)' % bases or ''
else:
metaclass = node.metaclass()
if metaclass and not node.has_metaclass_hack():
if bases:
bases = '(%s, metaclass=%s)' % (bases, metaclass.name)
else:
bases = '(metaclass=%s)' % metaclass.name
else:
bases = bases and '(%s)' % bases or ''
docs = node.doc and '\n%s"""%s"""' % (INDENT, node.doc) or ''
return '\n\n%sclass %s%s:%s\n%s\n' % (decorate, node.name, bases, docs,
self._stmt_list(node.body))
def visit_compare(self, node):
"""return an astroid.Compare node as string"""
rhs_str = ' '.join(['%s %s' % (op, expr.accept(self))
for op, expr in node.ops])
return '%s %s' % (node.left.accept(self), 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])
return 'for %s in %s%s' % (node.target.accept(self),
node.iter.accept(self), ifs)
def visit_const(self, node):
"""return an astroid.Const node as string"""
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_getattr(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(['%s: %s' % (key.accept(self),
value.accept(self))
for key, value in node.items])
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_discard(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, %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_from(self, node):
"""return an astroid.From node as string"""
return 'from %s import %s' % ('.' * (node.level or 0) + node.modname,
_import_string(node.names))
def visit_function(self, node):
"""return an astroid.Function node as string"""
decorate = node.decorators and node.decorators.accept(self) or ''
docs = node.doc and '\n%s"""%s"""' % (INDENT, node.doc) or ''
return '\n%sdef %s(%s):%s\n%s' % (decorate, node.name, node.args.accept(self),
docs, self._stmt_list(node.body))
def visit_genexpr(self, node):
"""return an astroid.GenExpr node as string"""
return '(%s %s)' % (node.elt.accept(self),
' '.join([n.accept(self) for n in node.generators]))
def visit_getattr(self, node):
"""return an astroid.Getattr node as string"""
return '%s.%s' % (node.expr.accept(self), 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.orelse:# XXX use elif ???
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' % (node.body.accept(self),
node.test.accept(self),
node.orelse.accept(self))
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"""
return '%s=%s' % (node.arg, node.value.accept(self))
def visit_lambda(self, node):
"""return an astroid.Lambda node as string"""
return 'lambda %s: %s' % (node.args.accept(self),
node.body.accept(self))
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 = node.doc and '"""%s"""\n\n' % node.doc or ''
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_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.inst:
if node.tback:
return 'raise %s, %s, %s' % (node.exc.accept(self),
node.inst.accept(self),
node.tback.accept(self))
return 'raise %s, %s' % (node.exc.accept(self),
node.inst.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.value:
return 'return %s' % node.value.accept(self)
else:
return 'return'
def visit_index(self, node):
"""return a 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 a astroid.Slice node as string"""
lower = node.lower and node.lower.accept(self) or ''
upper = node.upper and node.upper.accept(self) or ''
step = node.step and node.step.accept(self) or ''
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"""
return '%s[%s]' % (node.value.accept(self), node.slice.accept(self))
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, node.operand.accept(self))
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 and (" " + node.value.accept(self)) or ""
expr = 'yield' + yi_val
if node.parent.is_statement:
return expr
else:
return "(%s)" % (expr,)
class AsStringVisitor3k(AsStringVisitor):
"""AsStringVisitor3k overwrites some AsStringVisitor methods"""
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_nonlocal(self, node):
"""return an astroid.Nonlocal node as string"""
return 'nonlocal %s' % ', '.join(node.names)
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_starred(self, node):
"""return Starred node as string"""
return "*" + node.value.accept(self)
def visit_yieldfrom(self, node):
""" Return an astroid.YieldFrom node as string. """
yi_val = node.value and (" " + node.value.accept(self)) or ""
expr = 'yield from' + yi_val
if node.parent.is_statement:
return expr
else:
return "(%s)" % (expr,)
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)
if sys.version_info >= (3, 0):
AsStringVisitor = AsStringVisitor3k
# this visitor is stateless, thus it can be reused
to_code = AsStringVisitor()
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