AppPkg/Applications/Python/Python-2.7.2/Lib/lib2to3/fixes/fix_paren.py

   1 """Fixer that addes parentheses where they are required
   2
   3 This converts ``[x for x in 1, 2]`` to ``[x for x in (1, 2)]``."""
   4
   5 # By Taek Joo Kim and Benjamin Peterson
   6
   7 # Local imports
   8 from .. import fixer_base
   9 from ..fixer_util import LParen, RParen
  10
  11 # XXX This doesn't support nested for loops like [x for x in 1, 2 for x in 1, 2]
  12 class FixParen(fixer_base.BaseFix):
  13     BM_compatible = True
  14
  15     PATTERN = """
  16         atom< ('[' | '(')
  17             (listmaker< any
  18                 comp_for<
  19                     'for' NAME 'in'
  20                     target=testlist_safe< any (',' any)+ [',']
  21                      >
  22                     [any]
  23                 >
  24             >
  25             |
  26             testlist_gexp< any
  27                 comp_for<
  28                     'for' NAME 'in'
  29                     target=testlist_safe< any (',' any)+ [',']
  30                      >
  31                     [any]
  32                 >
  33             >)
  34         (']' | ')') >
  35     """
  36
  37     def transform(self, node, results):
  38         target = results["target"]
  39
  40         lparen = LParen()
  41         lparen.prefix = target.prefix
  42         target.prefix = u"" # Make it hug the parentheses
  43         target.insert_child(0, lparen)
  44         target.append_child(RParen())