python - 如何使用 Python 捕获输出并同时显示它？

Question

我有一个运行时间很长的作业，它运行了几分钟然后重新启动。该任务输出我这样捕获的各种信息:

output = subprocess.Popen(cmd,stdout=subprocess.PIPE).communicate()

问题是，我一次只会获得整个输出。我想在程序将其发送到标准输出时显示输出，同时仍将其推回缓冲区(我需要检查输出中是否存在某些字符串)。在 Ruby 中，我会这样做:

IO.popen(cmd) do |io|
  io.each_line do |line|
    puts line
    buffer << line
  end
end

Answer 1

你可以试试这样的:

cmd = ["./my_program.sh"]
p = subprocess.Popen( cmd, shell=False, stdout=subprocess.PIPE)   # launch the process
while p.poll() is None:          # check if the process is still alive
    out = p.stdout.readline()    # if it is still alive, grab the output
    do_something_with(out)       # do what you want with it