symbian-qemu-0.9.1-12/python-2.6.1/Lib/lib2to3/fixes/fix_print.py
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0:ffa851df0825 1:2fb8b9db1c86
       
     1 # Copyright 2006 Google, Inc. All Rights Reserved.
       
     2 # Licensed to PSF under a Contributor Agreement.
       
     3 
       
     4 """Fixer for print.
       
     5 
       
     6 Change:
       
     7     'print'          into 'print()'
       
     8     'print ...'      into 'print(...)'
       
     9     'print ... ,'    into 'print(..., end=" ")'
       
    10     'print >>x, ...' into 'print(..., file=x)'
       
    11 
       
    12 No changes are applied if print_function is imported from __future__
       
    13 
       
    14 """
       
    15 
       
    16 # Local imports
       
    17 from .. import patcomp
       
    18 from .. import pytree
       
    19 from ..pgen2 import token
       
    20 from .. import fixer_base
       
    21 from ..fixer_util import Name, Call, Comma, String, is_tuple
       
    22 
       
    23 
       
    24 parend_expr = patcomp.compile_pattern(
       
    25               """atom< '(' [atom|STRING|NAME] ')' >"""
       
    26               )
       
    27 
       
    28 
       
    29 class FixPrint(fixer_base.ConditionalFix):
       
    30 
       
    31     PATTERN = """
       
    32               simple_stmt< any* bare='print' any* > | print_stmt
       
    33               """
       
    34 
       
    35     skip_on = '__future__.print_function'
       
    36 
       
    37     def transform(self, node, results):
       
    38         assert results
       
    39 
       
    40         if self.should_skip(node):
       
    41             return
       
    42 
       
    43         bare_print = results.get("bare")
       
    44 
       
    45         if bare_print:
       
    46             # Special-case print all by itself
       
    47             bare_print.replace(Call(Name("print"), [],
       
    48                                prefix=bare_print.get_prefix()))
       
    49             return
       
    50         assert node.children[0] == Name("print")
       
    51         args = node.children[1:]
       
    52         if len(args) == 1 and parend_expr.match(args[0]):
       
    53             # We don't want to keep sticking parens around an
       
    54             # already-parenthesised expression.
       
    55             return
       
    56 
       
    57         sep = end = file = None
       
    58         if args and args[-1] == Comma():
       
    59             args = args[:-1]
       
    60             end = " "
       
    61         if args and args[0] == pytree.Leaf(token.RIGHTSHIFT, ">>"):
       
    62             assert len(args) >= 2
       
    63             file = args[1].clone()
       
    64             args = args[3:] # Strip a possible comma after the file expression
       
    65         # Now synthesize a print(args, sep=..., end=..., file=...) node.
       
    66         l_args = [arg.clone() for arg in args]
       
    67         if l_args:
       
    68             l_args[0].set_prefix("")
       
    69         if sep is not None or end is not None or file is not None:
       
    70             if sep is not None:
       
    71                 self.add_kwarg(l_args, "sep", String(repr(sep)))
       
    72             if end is not None:
       
    73                 self.add_kwarg(l_args, "end", String(repr(end)))
       
    74             if file is not None:
       
    75                 self.add_kwarg(l_args, "file", file)
       
    76         n_stmt = Call(Name("print"), l_args)
       
    77         n_stmt.set_prefix(node.get_prefix())
       
    78         return n_stmt
       
    79 
       
    80     def add_kwarg(self, l_nodes, s_kwd, n_expr):
       
    81         # XXX All this prefix-setting may lose comments (though rarely)
       
    82         n_expr.set_prefix("")
       
    83         n_argument = pytree.Node(self.syms.argument,
       
    84                                  (Name(s_kwd),
       
    85                                   pytree.Leaf(token.EQUAL, "="),
       
    86                                   n_expr))
       
    87         if l_nodes:
       
    88             l_nodes.append(Comma())
       
    89             n_argument.set_prefix(" ")
       
    90         l_nodes.append(n_argument)