Python函数运行太快了吗？

Question

我正在编写一个脚本（Python 2.7.10），以登录到网络设备并收集供应商可能要求的诊断信息。 这很简单，但是我遇到了一个有趣的问题（至少对我来说）。

我已经用尽了有限的知识。

这是一段调用函数运行的代码：

elif args.hostname and args.username and args.jtac and args.commands and args.shell:
    print("RUN FOR SINGLE HOST w/ SHELL AND CLI COMMANDS")
    open_ssh_session(args.hostname, args.username, password)
    commands_and_iterations_cli(args.hostname, args.jtac, args.iterations, float(args.interval))
    commands_and_iterations_shell(args.username, args.hostname, args.jtac, args.iterations, float(args.interval))
    single_core_dump(args.hostname, args.username, password, args.jtac)
    pull_files_from_juniper_device(args.hostname, args.username, password, args.jtac)
    push_files_to_juniper_sftp(args.hostname, args.username, password, args.jtac)

所以我有2个功能：

def commands_and_iterations_cli(hostname, jtac, iterations, interval):

    print("Enter each JUNOS CLI command on separate lines, press CTRL+D when finished.\n"
          "NOTE: Valid CLI commands only, DO NOT input shell commands here!\n") 

    # Take user input, enter a command on each new line, send EOF to indicate that you're done.
    cli_commands = sys.stdin.readlines()

    # Instantiate user shell.
    channel = client.invoke_shell()

    # Take each line from given input, and iterate over hostname.
    for line in cli_commands:
        line = line.strip()
        iter_counter = 0
        print("Running {}, {} times, every {} seconds.".format(line, str(iterations), interval))
        while iter_counter < iterations:
            iter_counter = iter_counter + 1
            channel.send(line +' | save "{}-{}-{}"\n'.format(hostname, jtac, line))
            time.sleep(interval)


def commands_and_iterations_shell(username, hostname, jtac, iterations, interval):  

    print("Enter each shell command on separate lines, press CTRL+D when finished.\n"
          "NOTE: Valid shell commands only, DO NOT input JUNOS CLI commands here!\n"
          "** ENSURE COMMANDS ARE SAFE TO RUN IN PRODUCTION IF DOING SO! **\n") 

    # Take user input, enter a command on each new line, send EOF to indicate that you're done.
    shell_commands = sys.stdin.readlines()

    # Prompt for hostname's root password to enter root shell.    
    print("Enter root password for {}:\n".format(hostname))
    rootpass = getpass.getpass()

    # Instantiate user shell.
    channel = client.invoke_shell()

    # Start root shell.
    channel.send("start shell user root\n")

    # Let the prompt become available.
    time.sleep(1)

    # Send the password and let the root prompt return.
    channel.send(rootpass+"\n")
    time.sleep(1)

    # Take each line from given input, and iterate over hostname.
    for line in shell_commands:
        line = line.strip()
        print("Running {}, {} times, every {} seconds.".format(line, str(iterations), interval))
        iter_counter = 0
        while iter_counter != iterations:
            channel.send(line +' >> "/var/home/{}/{}-{}-{}" \n'.format(username, hostname, jtac, line))
            time.sleep(interval)
            iter_counter = iter_counter + 1
            print(iter_counter)

如果我独立运行commands_and_iterations_cli()或commands_and_iterations_shell()则代码可以完美运行。 但是，当我尝试两者（给出的示例）时，CLI函数将正确运行，然后当需要运行shell函数时，shell函数将在其中打印文本，并提示输入root密码，然后立即跳过在不提示输入命令的情况下转到下一个功能。 我什至尝试过在shell函数运行之前让它休眠30秒，并且行为如下。

谢谢大家

Answer 1

这是行不通的，因为您必须使用CTRL+D退出sys.stdin.readlines() ，该操作会关闭流并进一步对其进行任何调用（即返回空列表）。