gistfile1.txt

class LogLine(object):
  def __init__(self,raw_line):
    self.pid       = pid(raw_line)
    self.ip        = ip(raw_line)
    self.timestamp = timestamp(raw_line)

  def pid(self,line):
    pass

  def ip(self,line):
    pass

  def timestamp(self,line):
    pass

if __name__ == '__main__':
  PIDS_IN_PROCESSING = {}
  IP_DURATIONS = []

  for line in open("you/file.log"):
    log_line = LogLine(line)

    # means it's a CLOSE log line since we have seen it before
    if log_line.pid in PIDS_IN_PROCESSING:
      accept_line = PIDS_IN_PROCESSING[log_line.pid]
      duration = (accept_line.ip,log_line.timestamp - accept_line.timestamp)
      IP_DURATIONS.append( duration )
      delete PIDS_IN_PROCESSING[log_line.pid]
    # first time we have seen the log line
    else:
      PIDS_IN_PROCESSING[log_line.pid] = log_line

  print IP_DURATIONS