1 """Fixer for sys.exc_{type, value, traceback}

     2 

     3 sys.exc_type -> sys.exc_info()[0]

     4 sys.exc_value -> sys.exc_info()[1]

     5 sys.exc_traceback -> sys.exc_info()[2]

     6 """

     7 

     8 # By Jeff Balogh and Benjamin Peterson

     9 

    10 # Local imports

    11 from .. import fixer_base

    12 from ..fixer_util import Attr, Call, Name, Number, Subscript, Node, syms

    13 

    14 class FixSysExc(fixer_base.BaseFix):

    15     # This order matches the ordering of sys.exc_info().

    16     exc_info = ["exc_type", "exc_value", "exc_traceback"]

    17     PATTERN = """

    18               power< 'sys' trailer< dot='.' attribute=(%s) > >

    19               """ % '|'.join("'%s'" % e for e in exc_info)

    20 

    21     def transform(self, node, results):

    22         sys_attr = results["attribute"][0]

    23         index = Number(self.exc_info.index(sys_attr.value))

    24 

    25         call = Call(Name("exc_info"), prefix=sys_attr.get_prefix())

    26         attr = Attr(Name("sys"), call)

    27         attr[1].children[0].set_prefix(results["dot"].get_prefix())

    28         attr.append(Subscript(index))

    29         return Node(syms.power, attr, prefix=node.get_prefix())