new_contents: # -*- coding: utf-8 -*-
  
  import sys
  
  array = [0] # array of bytes
  ptr = 0 # data pointer
  
  def readNoLoop(char):
    global ptr
    # Increment/Decrement the byte at the data pointer
    if char=='+':
      array[ptr] += 1
    elif char=='-':
      array[ptr] -= 1
      if array[ptr] < 0:
        raise ValueError("Negative value in array")
    # Increment/Decrement the data pointer
    elif char=='>':
      ptr += 1
      while(ptr>=len(array)-1):
        array.append(0)
    elif char=='<':
      ptr -= 1
      if ptr < 0:
        raise ValueError("Negative value of pointer")
    # Output the byte at the data pointer
    elif char=='.':
      sys.stdout.write(chr(array[ptr]))
    # Store one byte of input in the byte at the data pointer 
    elif char==',':
      array[ptr] = ord(sys.stdin.read(1))
    #print ptr, array
        
  def interpret(charChain):
    it = 0
    loopBegin = []
    while(it<len(charChain)):
      if charChain[it]=='[':
        loopBegin.append(it)
      elif charChain[it]==']':
        subChain = charChain[loopBegin[-1]+1:it]
        while(array[ptr]>0):
          interpret(subChain)
        loopBegin.pop()
      else:
        readNoLoop(charChain[it])
      it+=1
  
  if __name__ == "__main__":
  
    cmd = '++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.'
    #cmd = '[,.]'
    try:
      interpret(cmd)
    except:
      raise
subject: Add the source file