text: u"""
  Fixer for:
  (a,)* *b (,c)* [,] = s
  for (a,)* *b (,c)* [,] in d: ...
  """
  
  from lib2to3 import fixer_base
  from itertools import count
  from lib2to3.fixer_util import (
      Assign,
      Comma,
      Call,
      Newline,
      Name,
      Number,
      token,
      syms,
      Node,
      Leaf,
  )
  from libfuturize.fixer_util import indentation, suitify, commatize
  
  # from libfuturize.fixer_util import Assign, Comma, Call, Newline, Name, Number, indentation, suitify, commatize, token, syms, Node, Leaf
  
  
  def assignment_source(num_pre, num_post, LISTNAME, ITERNAME):
      u"""
      Accepts num_pre and num_post, which are counts of values
      before and after the starg (not including the starg)
      Returns a source fit for Assign() from fixer_util
      """
      children = []
      pre = unicode(num_pre)
      post = unicode(num_post)
      # This code builds the assignment source from lib2to3 tree primitives.
      # It's not very readable, but it seems like the most correct way to do it.
      if num_pre > 0:
          pre_part = Node(
              syms.power,
              [
                  Name(LISTNAME),
                  Node(
                      syms.trailer,
                      [
                          Leaf(token.LSQB, u"["),
                          Node(syms.subscript, [Leaf(token.COLON, u":"), Number(pre)]),
                          Leaf(token.RSQB, u"]"),
                      ],
                  ),
              ],
          )
          children.append(pre_part)
          children.append(Leaf(token.PLUS, u"+", prefix=u" "))
      main_part = Node(
          syms.power,
          [
              Leaf(token.LSQB, u"[", prefix=u" "),
              Name(LISTNAME),
              Node(
                  syms.trailer,
                  [
                      Leaf(token.LSQB, u"["),
                      Node(
                          syms.subscript,
                          [
                              Number(pre) if num_pre > 0 else Leaf(1, u""),
                              Leaf(token.COLON, u":"),
                              Node(syms.factor, [Leaf(token.MINUS, u"-"), Number(post)])
                              if num_post > 0
                              else Leaf(1, u""),
                          ],
                      ),
                      Leaf(token.RSQB, u"]"),
                      Leaf(token.RSQB, u"]"),
                  ],
              ),
          ],
      )
      children.append(main_part)
      if num_post > 0:
          children.append(Leaf(token.PLUS, u"+", prefix=u" "))
          post_part = Node(
              syms.power,
              [
                  Name(LISTNAME, prefix=u" "),
                  Node(
                      syms.trailer,
                      [
                          Leaf(token.LSQB, u"["),
                          Node(
                              syms.subscript,
                              [
                                  Node(
                                      syms.factor, [Leaf(token.MINUS, u"-"), Number(post)]
                                  ),
                                  Leaf(token.COLON, u":"),
                              ],
                          ),
                          Leaf(token.RSQB, u"]"),
                      ],
                  ),
              ],
          )
          children.append(post_part)
      source = Node(syms.arith_expr, children)
      return source
  
  
  class FixUnpacking(fixer_base.BaseFix):
  
      PATTERN = u"""
      expl=expr_stmt< testlist_star_expr<
          pre=(any ',')*
              star_expr< '*' name=NAME >
          post=(',' any)* [','] > '=' source=any > |
      impl=for_stmt< 'for' lst=exprlist<
          pre=(any ',')*
              star_expr< '*' name=NAME >
          post=(',' any)* [','] > 'in' it=any ':' suite=any>"""
  
      def fix_explicit_context(self, node, results):
          pre, name, post, source = (
              results.get(n) for n in (u"pre", u"name", u"post", u"source")
          )
          pre = [n.clone() for n in pre if n.type == token.NAME]
          name.prefix = u" "
          post = [n.clone() for n in post if n.type == token.NAME]
          target = [n.clone() for n in commatize(pre + [name.clone()] + post)]
          # to make the special-case fix for "*z, = ..." correct with the least
          # amount of modification, make the left-side into a guaranteed tuple
          target.append(Comma())
          source.prefix = u""
          setup_line = Assign(Name(self.LISTNAME), Call(Name(u"list"), [source.clone()]))
          power_line = Assign(
              target, assignment_source(len(pre), len(post), self.LISTNAME, self.ITERNAME)
          )
          return setup_line, power_line
  
      def fix_implicit_context(self, node, results):
          u"""
          Only example of the implicit context is
          a for loop, so only fix that.
          """
          pre, name, post, it = (
              results.get(n) for n in (u"pre", u"name", u"post", u"it")
          )
          pre = [n.clone() for n in pre if n.type == token.NAME]
          name.prefix = u" "
          post = [n.clone() for n in post if n.type == token.NAME]
          target = [n.clone() for n in commatize(pre + [name.clone()] + post)]
          # to make the special-case fix for "*z, = ..." correct with the least
          # amount of modification, make the left-side into a guaranteed tuple
          target.append(Comma())
          source = it.clone()
          source.prefix = u""
          setup_line = Assign(
              Name(self.LISTNAME), Call(Name(u"list"), [Name(self.ITERNAME)])
          )
          power_line = Assign(
              target, assignment_source(len(pre), len(post), self.LISTNAME, self.ITERNAME)
          )
          return setup_line, power_line
  
      def transform(self, node, results):
          u"""
          a,b,c,d,e,f,*g,h,i = range(100) changes to
          _3to2list = list(range(100))
          a,b,c,d,e,f,g,h,i, = _3to2list[:6] + [_3to2list[6:-2]] + _3to2list[-2:]
  
          and
  
          for a,b,*c,d,e in iter_of_iters: do_stuff changes to
          for _3to2iter in iter_of_iters:
              _3to2list = list(_3to2iter)
              a,b,c,d,e, = _3to2list[:2] + [_3to2list[2:-2]] + _3to2list[-2:]
              do_stuff
          """
          self.LISTNAME = self.new_name(u"_3to2list")
          self.ITERNAME = self.new_name(u"_3to2iter")
          expl, impl = results.get(u"expl"), results.get(u"impl")
          if expl is not None:
              setup_line, power_line = self.fix_explicit_context(node, results)
              setup_line.prefix = expl.prefix
              power_line.prefix = indentation(expl.parent)
              setup_line.append_child(Newline())
              parent = node.parent
              i = node.remove()
              parent.insert_child(i, power_line)
              parent.insert_child(i, setup_line)
          elif impl is not None:
              setup_line, power_line = self.fix_implicit_context(node, results)
              suitify(node)
              suite = [k for k in node.children if k.type == syms.suite][0]
              setup_line.prefix = u""
              power_line.prefix = suite.children[1].value
              suite.children[2].prefix = indentation(suite.children[2])
              suite.insert_child(2, Newline())
              suite.insert_child(2, power_line)
              suite.insert_child(2, Newline())
              suite.insert_child(2, setup_line)
              results.get(u"lst").replace(Name(self.ITERNAME, prefix=u" "))
  