Source Code for Module osh.command.gen

  1  # osh 
  2  # Copyright (C) Jack Orenstein <jao@geophile.com> 
  3  # 
  4  # This program is free software; you can redistribute it and/or modify 
  5  # it under the terms of the GNU General Public License as published by 
  6  # the Free Software Foundation; either version 2 of the License, or 
  7  # (at your option) any later version. 
  8  # 
  9  # This program is distributed in the hope that it will be useful, 
 10  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 11  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 12  # GNU General Public License for more details. 
 13  # 
 14  # You should have received a copy of the GNU General Public License 
 15  # along with this program; if not, write to the Free Software 
 16  # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 17   
 18  """C{gen [-p PAD] [COUNT [START]]} 
 19   
 20  Generate a sequence of C{COUNT} integers, starting at C{START}. If 
 21  C{START} is not specified, then the sequence starts at 0. If no 
 22  arguments are specified, then the sequence starts at 0 and does not 
 23  terminate. 
 24   
 25  If the C{-p} flag is specified, then the generated integers are 
 26  converted to strings and left padded so that each string contains 
 27  C{PAD} characters. C{len(str(COUNT + START))} must not exceed C{PAD}. 
 28  """ 
 29   
 30  import osh.core 
 31  import osh.args 
 32   
 33  Option = osh.args.Option 
 34   
 35  # CLI 
 36 -def _gen(): 
 37      return _Gen() 
 38   
 39  # API 
 40 -def gen(count = None, start = 0, pad = None): 
 41      """Generate a sequence of C{count} integers, starting at C{start}. If no arguments 
 42      are provided then the sequence starts at 0 and does not terminate. If C{pad} is 
 43      specified, and is an integer, then the output values are strings, padded to the 
 44      specified length. The length of the generated strings must not exceed C{pad}. 
 45      """ 
 46      args = [count, start] 
 47      if pad is not None: 
 48          args.append(Option('-p', pad)) 
 49      return _Gen().process_args(*args) 
 50   
 51 -class _Gen(osh.core.Generator): 
 52   
 53      _count = None 
 54      _start = None 
 55      _format = None 
 56   
 57      # object interface 
 58   
 59 -    def __init__(self): 
 60          osh.core.Generator.__init__(self, 'p:', (0, 2)) 
 61   
 62      # BaseOp interface 
 63       
 64 -    def doc(self): 
 65          return __doc__ 
 66   
 67 -    def setup(self): 
 68          args = self.args() 
 69          self._count = args.next_int() 
 70          self._start = args.next_int() 
 71          pad = args.int_arg('-p') 
 72          if self._start is None: 
 73              self._start = 0 
 74          if pad is not None: 
 75              self._format = '%%0%sd' % pad 
 76              if len(str(self._count + self._start)) > pad: 
 77                  self.usage() 
 78          if args.has_next(): 
 79              self.usage() 
 80   
 81   
 82      # Generator interface 
 83       
 84 -    def execute(self): 
 85          if self._count is None: 
 86              n = 0 
 87              while True: 
 88                  self._format_and_send(n) 
 89                  n += 1 
 90          else: 
 91              for x in xrange(self._start, self._start + self._count): 
 92                  self._format_and_send(x) 
 93   
 94      # For use by this class 
 95   
 96 -    def _format_and_send(self, x): 
 97          if self._format is None: 
 98              self.send(x) 
 99          else: 
100              self.send(self._format % x) 
101