python代码片段——不断尝试执行cmd

"""
cmd: 命令
tries: 尝试次数
timeout: 每一次尝试执行时的时间长度
interval: 每一次尝试执行间的时间间隔
"""

@staticmethod
def execute_shell(cmd, tries=1, timeout=10, interval=10):
index = 0
errorContent = ""
while True:
if(index >= tries):
raise Exception(-1,"[{0}] try {1} times still fail:{2}".format(cmd,tries,errorContent))

if timeout:
end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
sub = subprocess.Popen(cmd, stdout=subprocess.PIPE,stderr=subprocess.PIPE, stdin=subprocess.PIPE,shell=True)

while sub.poll() is None:
time.sleep(0.1)
if timeout:
if end_time <= datetime.datetime.now():
Toolkit.kill_child_processes(sub.pid)
stdout,stderr = sub.communicate()

if sub.returncode == 0:
return sub.returncode,stdout
else:
errorContent = stderr
time.sleep(interval)
index += 1