tea break

second_code.py

# coding: utf-8
from copy import copy

class SimpleBars(object):
  def __init__(self,arg):
    """ Initializing a sequence as list """
    self.current = [c for c in arg]
  def apply_rules(self):
    """ Applying rules to current sequence """
    # Rule1:
    #   'T' -> 'j'
    next_seq = copy(self.current)
    for i, v in enumerate(self.current):
      if v == 'T': next_seq[i] = 'j'
    # Rule2:
    #   'i' -> 'iTi', (i+i|i+j|j+j|j+i) -> ' '
    next_seq2 = copy(next_seq)
    for i, v in enumerate(next_seq):
      if v != 'i': continue
      next_seq2[i] = 'T'
      targets = [i-1,
                (0 if len(next_seq2) <= i+1 else i+1)]
      for t in targets:
        if next_seq2[t] == 'i' or next_seq2[t] == 'j':
          next_seq2[t] = ' '
        else:
          next_seq2[t] = 'i'
    # Replace 'j' to 'i'
    self.current = [c for c in ''.join(next_seq2).replace('j', 'i')]
  def next(self):
   """ Generate next sequences from current sequences """
   self.apply_rules()
   return ''.join(self.current)