如何使用Python同时捕获输出并显示它？

Question

我有一个很长的工作,运行几分钟,然后重新启动.该任务输出我捕获的各种信息:

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

问题是,我一次只能得到整个输出.我想显示输出,因为程序将它发送到stdout,同时仍然将其推回缓冲区(我需要检查输出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

你可以尝试这样的事情:

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