1"""Fixer for generator.throw(E, V, T). 2 3g.throw(E) -> g.throw(E) 4g.throw(E, V) -> g.throw(E(V)) 5g.throw(E, V, T) -> g.throw(E(V).with_traceback(T)) 6 7g.throw("foo"[, V[, T]]) will warn about string exceptions.""" 8# Author: Collin Winter 9 10# Local imports 11from .. import pytree 12from ..pgen2 import token 13from .. import fixer_base 14from ..fixer_util import Name, Call, ArgList, Attr, is_tuple 15 16class FixThrow(fixer_base.BaseFix): 17 BM_compatible = True 18 PATTERN = """ 19 power< any trailer< '.' 'throw' > 20 trailer< '(' args=arglist< exc=any ',' val=any [',' tb=any] > ')' > 21 > 22 | 23 power< any trailer< '.' 'throw' > trailer< '(' exc=any ')' > > 24 """ 25 26 def transform(self, node, results): 27 syms = self.syms 28 29 exc = results["exc"].clone() 30 if exc.type is token.STRING: 31 self.cannot_convert(node, "Python 3 does not support string exceptions") 32 return 33 34 # Leave "g.throw(E)" alone 35 val = results.get(u"val") 36 if val is None: 37 return 38 39 val = val.clone() 40 if is_tuple(val): 41 args = [c.clone() for c in val.children[1:-1]] 42 else: 43 val.prefix = u"" 44 args = [val] 45 46 throw_args = results["args"] 47 48 if "tb" in results: 49 tb = results["tb"].clone() 50 tb.prefix = u"" 51 52 e = Call(exc, args) 53 with_tb = Attr(e, Name(u'with_traceback')) + [ArgList([tb])] 54 throw_args.replace(pytree.Node(syms.power, with_tb)) 55 else: 56 throw_args.replace(Call(exc, args)) 57