pyx/pycompat.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2011 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2011 André Wobst <wobsta@users.sourceforge.net>
   6 #
   7 # This file is part of PyX (http://pyx.sourceforge.net/).
   8 #
   9 # PyX is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 2 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # PyX is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with PyX; if not, write to the Free Software
  21 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  22
  23 class _marker: pass
  24
  25 def popen(cmd, mode="r", bufsize=_marker):
  26     try:
  27         import subprocess
  28         if mode[0] not in "rw" or "r" in mode[1:] or "w" in mode[1:]:
  29             raise ValueError("read or write mode expected")
  30         if mode[0] == "r":
  31             kwargs = {"stdout": subprocess.PIPE}
  32         else:
  33             kwargs = {"stdin": subprocess.PIPE}
  34         if bufsize is not _marker:
  35             kwargs["bufsize"] = bufsize
  36         pipes = subprocess.Popen(cmd, shell=True, **kwargs)
  37         if mode[0] == "r":
  38             return pipes.stdout
  39         else:
  40             return pipes.stdin
  41     except ImportError:
  42         import os
  43         if bufsize is _marker:
  44             return os.popen(cmd, mode)
  45         else:
  46             return os.popen(cmd, mode, bufsize)
  47
  48 try:
  49     any = any
  50 except NameError:
  51     def any(iterable):
  52         for element in iterable:
  53             if element:
  54                 return True
  55         return False
  56
  57 try:
  58     set = set
  59 except NameError:
  60     # Python 2.3
  61     from sets import Set as set