如何使用for循环根据posixct for log files之间的差异创建新变量

import datetime

log_file = open("logfile.txt", "r")

previous_timestamp = None
for line in log_file:
    timestamp_str = line.split()[0]  # Assuming timestamp is the first element in each line
    current_timestamp = datetime.datetime.strptime(timestamp_str, "%Y-%m-%d %H:%M:%S")  # Adjust the format according to your log timestamp format
    
    if previous_timestamp is not None:
        time_difference = (current_timestamp - previous_timestamp).total_seconds()
        # Create new variable or perform desired operations with the time difference
        
    previous_timestamp = current_timestamp

log_file.close()

log_file <- file("logfile.txt", "r")

previous_timestamp <- NULL
while (length(line <- readLines(log_file, n = 1, warn = FALSE)) > 0) {
  timestamp_str <- strsplit(line, " ")[[1]][1]  # Assuming timestamp is the first element in each line
  current_timestamp <- as.POSIXct(timestamp_str, format = "%Y-%m-%d %H:%M:%S")  # Adjust the format according to your log timestamp format
  
  if (!is.null(previous_timestamp)) {
    time_difference <- difftime(current_timestamp, previous_timestamp, units = "secs")
    # Create new variable or perform desired operations with the time difference
    
  }
  
  previous_timestamp <- current_timestamp
}

close(log_file)