python – 如果存在则检查文件然后追加记录

我正在创建一个包含逐行记录的日志文件.

1-如果文件不存在,则应创建文件并追加标题行和记录
2-如果存在,请检查第一行中的文本timeStamp.如果存在,则附加记录,否则添加标题列并记录自身

我试过了w,a和r;没有什么对我有用.以下是我的代码:

logFile = open('Dump.log', 'r+')
datalogFile = log.readline()
if 'Timestamp' in datalogFile:
    logFile.write('%s\t%s\t%s\t%s\t\n'%(timestamp,logread,logwrite,log_skipped_noweight))
    logFile.flush()
else:
    logFile.write('Timestamp\t#Read\t#Write\t#e\n')
    logFile.flush()
    logFile.write('%s\t%s\t%s\t%s\t\n'%(timestamp,logread,logwrite,log_skipped))
    logFile.flush()

如果文件不存在,代码将失败

最佳答案 使用’a’模式:

logFile = open('Dump.log', 'a+')

描述:

a+
Open for reading and writing. The file is created if it does not
exist. The stream is positioned at the end of the file. Subsequent
writes to the file will always end up at the then current
end of file, irrespective of any intervening fseek(3) or similar

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