class ExpressionGenerator(object):
"""given an AST node, generates an equivalent literal Python
expression."""
def __init__(self, astnode):
self.buf = StringIO()
visitor.walk(astnode, self) # , walker=walker())
def value(self):
return self.buf.getvalue()
def operator(self, op, node, *args):
self.buf.write('(')
self.visit(node.left, *args)
self.buf.write(' %s ' % op)
self.visit(node.right, *args)
self.buf.write(')')
def booleanop(self, op, node, *args):
self.visit(node.nodes[0])
for n in node.nodes[1:]:
self.buf.write(' ' + op + ' ')
self.visit(n, *args)
def visitConst(self, node, *args):
self.buf.write(repr(node.value))
def visitAssName(self, node, *args):
# TODO: figure out OP_ASSIGN, other OP_s
self.buf.write(node.name)
def visitName(self, node, *args):
self.buf.write(node.name)
def visitMul(self, node, *args):
self.operator('*', node, *args)
def visitAnd(self, node, *args):
self.booleanop('and', node, *args)
def visitOr(self, node, *args):
self.booleanop('or', node, *args)
def visitBitand(self, node, *args):
self.booleanop('&', node, *args)
def visitBitor(self, node, *args):
self.booleanop('|', node, *args)
def visitBitxor(self, node, *args):
self.booleanop('^', node, *args)
def visitAdd(self, node, *args):
self.operator('+', node, *args)
def visitGetattr(self, node, *args):
self.visit(node.expr, *args)
self.buf.write('.%s' % node.attrname)
def visitSub(self, node, *args):
self.operator('-', node, *args)
def visitNot(self, node, *args):
self.buf.write('not ')
self.visit(node.expr)
def visitDiv(self, node, *args):
self.operator('/', node, *args)
def visitFloorDiv(self, node, *args):
self.operator('//', node, *args)
def visitSubscript(self, node, *args):
self.visit(node.expr)
self.buf.write('[')
[self.visit(x) for x in node.subs]
self.buf.write(']')
def visitUnarySub(self, node, *args):
self.buf.write('-')
self.visit(node.expr)
def visitUnaryAdd(self, node, *args):
self.buf.write('-')
self.visit(node.expr)
def visitSlice(self, node, *args):
self.visit(node.expr)
self.buf.write('[')
if node.lower is not None:
self.visit(node.lower)
self.buf.write(':')
if node.upper is not None:
self.visit(node.upper)
self.buf.write(']')
def visitDict(self, node):
self.buf.write('{')
c = node.getChildren()
for i in range(0, len(c), 2):
self.visit(c[i])
self.buf.write(': ')
self.visit(c[i + 1])
if i < len(c) - 2:
self.buf.write(', ')
self.buf.write('}')
def visitTuple(self, node):
self.buf.write('(')
c = node.getChildren()
for i in range(0, len(c)):
self.visit(c[i])
if i < len(c) - 1:
self.buf.write(', ')
self.buf.write(')')
def visitList(self, node):
self.buf.write('[')
c = node.getChildren()
for i in range(0, len(c)):
self.visit(c[i])
if i < len(c) - 1:
self.buf.write(', ')
self.buf.write(']')
def visitListComp(self, node):
self.buf.write('[')
self.visit(node.expr)
self.buf.write(' ')
for n in node.quals:
self.visit(n)
self.buf.write(']')
def visitListCompFor(self, node):
self.buf.write(' for ')
self.visit(node.assign)
self.buf.write(' in ')
self.visit(node.list)
for n in node.ifs:
self.visit(n)
def visitListCompIf(self, node):
self.buf.write(' if ')
self.visit(node.test)
def visitCompare(self, node):
self.visit(node.expr)
for tup in node.ops:
self.buf.write(tup[0])
self.visit(tup[1])
def visitCallFunc(self, node, *args):
self.visit(node.node)
self.buf.write('(')
if len(node.args):
self.visit(node.args[0])
for a in node.args[1:]:
self.buf.write(', ')
self.visit(a)
self.buf.write(')')
def visitLambda(self, node, *args):
self.buf.write('lambda ')
argnames = list(node.argnames)
kw = arg = None
if node.kwargs > 0:
kw = argnames.pop(-1)
if node.varargs > 0:
arg = argnames.pop(-1)
if arg:
argnames.append("*%s" % arg)
if kw:
argnames.append("**%s" % kw)
self.buf.write(", ".join(argnames))
self.buf.write(': ')
self.visit(node.code)
class ExpressionGenerator(object):
"""given an AST node, generates an equivalent literal Python
expression."""
def __init__(self, astnode):
self.buf = StringIO()
visitor.walk(astnode, self) # , walker=walker())
def value(self):
return self.buf.getvalue()
def operator(self, op, node, *args):
self.buf.write('(')
self.visit(node.left, *args)
self.buf.write(' %s ' % op)
self.visit(node.right, *args)
self.buf.write(')')
def booleanop(self, op, node, *args):
self.visit(node.nodes[0])
for n in node.nodes[1:]:
self.buf.write(' ' + op + ' ')
self.visit(n, *args)
def visitConst(self, node, *args):
self.buf.write(repr(node.value))
def visitAssName(self, node, *args):
# TODO: figure out OP_ASSIGN, other OP_s
self.buf.write(node.name)
def visitName(self, node, *args):
self.buf.write(node.name)
def visitMul(self, node, *args):
self.operator('*', node, *args)
def visitAnd(self, node, *args):
self.booleanop('and', node, *args)
def visitOr(self, node, *args):
self.booleanop('or', node, *args)
def visitBitand(self, node, *args):
self.booleanop('&', node, *args)
def visitBitor(self, node, *args):
self.booleanop('|', node, *args)
def visitBitxor(self, node, *args):
self.booleanop('^', node, *args)
def visitAdd(self, node, *args):
self.operator('+', node, *args)
def visitGetattr(self, node, *args):
self.visit(node.expr, *args)
self.buf.write('.%s' % node.attrname)
def visitSub(self, node, *args):
self.operator('-', node, *args)
def visitNot(self, node, *args):
self.buf.write('not ')
self.visit(node.expr)
def visitDiv(self, node, *args):
self.operator('/', node, *args)
def visitFloorDiv(self, node, *args):
self.operator('//', node, *args)
def visitSubscript(self, node, *args):
self.visit(node.expr)
self.buf.write('[')
[self.visit(x) for x in node.subs]
self.buf.write(']')
def visitUnarySub(self, node, *args):
self.buf.write('-')
self.visit(node.expr)
def visitUnaryAdd(self, node, *args):
self.buf.write('-')
self.visit(node.expr)
def visitSlice(self, node, *args):
self.visit(node.expr)
self.buf.write('[')
if node.lower is not None:
self.visit(node.lower)
self.buf.write(':')
if node.upper is not None:
self.visit(node.upper)
self.buf.write(']')
def visitDict(self, node):
self.buf.write('{')
c = node.getChildren()
for i in range(0, len(c), 2):
self.visit(c[i])
self.buf.write(': ')
self.visit(c[i + 1])
if i < len(c) - 2:
self.buf.write(', ')
self.buf.write('}')
def visitTuple(self, node):
self.buf.write('(')
c = node.getChildren()
for i in range(0, len(c)):
self.visit(c[i])
if i < len(c) - 1:
self.buf.write(', ')
self.buf.write(')')
def visitList(self, node):
self.buf.write('[')
c = node.getChildren()
for i in range(0, len(c)):
self.visit(c[i])
if i < len(c) - 1:
self.buf.write(', ')
self.buf.write(']')
def visitListComp(self, node):
self.buf.write('[')
self.visit(node.expr)
self.buf.write(' ')
for n in node.quals:
self.visit(n)
self.buf.write(']')
def visitListCompFor(self, node):
self.buf.write(' for ')
self.visit(node.assign)
self.buf.write(' in ')
self.visit(node.list)
for n in node.ifs:
self.visit(n)
def visitListCompIf(self, node):
self.buf.write(' if ')
self.visit(node.test)
def visitCompare(self, node):
self.visit(node.expr)
for tup in node.ops:
self.buf.write(tup[0])
self.visit(tup[1])
def visitCallFunc(self, node, *args):
self.visit(node.node)
self.buf.write('(')
if len(node.args):
self.visit(node.args[0])
for a in node.args[1:]:
self.buf.write(', ')
self.visit(a)
self.buf.write(')')
