保持子进程活着并继续给它命令?Python
问题描述
如果我使用给定命令在 python 中生成一个新的 subprocess(假设我使用 python 命令启动 python 解释器)，我如何将新数据发送到过程(通过 STDIN)?
If I spawn a new subprocess in python with a given command (let's say I start the python interpreter with the python command), how can I send new data to the process (via STDIN)?
解决方案
使用标准的subprocess模块.您使用 subprocess.Popen() 启动进程，它将在后台运行(即与您的 Python 程序同时运行).当您调用 Popen() 时，您可能希望将 stdin、stdout 和 stderr 参数设置为 subprocess.PIPE.然后就可以使用返回对象上的stdin、stdout和stderr字段来读写数据了.
Use the standard subprocess module. You use subprocess.Popen() to start the process, and it will run in the background (i.e. at the same time as your Python program). When you call Popen(), you probably want to set the stdin, stdout and stderr parameters to subprocess.PIPE. Then you can use the stdin, stdout and stderr fields on the returned object to write and read data.
未经测试的示例代码:
from subprocess import Popen, PIPE
# Run "cat", which is a simple Linux program that prints it's input.
process = Popen(['/bin/cat'], stdin=PIPE, stdout=PIPE)
process.stdin.write(b'Hello
')
process.stdin.flush()
print(repr(process.stdout.readline())) # Should print 'Hello
'
process.stdin.write(b'World
')
process.stdin.flush()
print(repr(process.stdout.readline())) # Should print 'World
'
# "cat" will exit when you close stdin. (Not all programs do this!)
process.stdin.close()
print('Waiting for cat to exit')
process.wait()
print('cat finished with return code %d' % process.returncode)
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