Question

以下是脚本的摘录（未经测试）

def start_custer():
    try:
        myidentifier=mydict['DescribeClustersResponse']['DescribeClustersResult']['Clusters'][0]['ClusterIdentifier']
    except IndexError:
        conn.restore_from_cluster_snapshot('vi-mar5-deliveryreport-new', mysnapidentifier, availability_zone='us-east-1a')

def stop_cluster():
    try:    
        myidentifier=mydict['DescribeClustersResponse']['DescribeClustersResult']['Clusters'][0]['ClusterIdentifier']
        conn.delete_cluster(myidentifier, skip_final_cluster_snapshot=False, final_cluster_snapshot_identifier=myvar)
    except:
        print "error"

这些功能在技术上（语法上）是否正确？
如何在调用python脚本时调用它们？我需要一次启动或停止群集，而不是两者。

Answer 1

对于第二个问题，我将通过argparse解析命令行：

import argparse

parser = argparse.ArgumentParser(description="Manage the cluster")
parser.add_argument("action", choices=["stop", "start"],
                    help="Action to perform")

args = parser.parse_args()
if args.action == "start":
    start_cluster()
if args.action == "stop":
    stop_cluster()

Answer 2

其他人向您展示了执行此操作的最佳方法，但是对于记录，您还可以从命令行执行此操作：

python -c "import cluster; cluster.start_cluster()"

（假设您的模块文件名为cluster.py - 如果没有，则相应地调整import语句。

这不像自己解析命令行这样用户友好，但它会在紧要关头完成。

Answer 3

1）如果您已在某处定义Syntactically并导入它，则conn正确无误！

2）

def stop_cluster():
    ## Your code

def fun():
    ## your code

if __name__ == "__main__":
    import sys
    globals()[sys.argv[1]]()

用法：

   python2.7 test_syn.py fun

Answer 4

我在你的脚本中添加了一个main函数来检查命令行参数，然后在没有提供有效参数的情况下提示你：

import sys

def start_custer():
    try:
        myidentifier=mydict['DescribeClustersResponse']['DescribeClustersResult']['Clusters'][0]['ClusterIdentifier']
    except IndexError:
        conn.restore_from_cluster_snapshot('vi-mar5-deliveryreport-new', mysnapidentifier, availability_zone='us-east-1a')

def stop_cluster():
    try:    
        myidentifier=mydict['DescribeClustersResponse']['DescribeClustersResult']['Clusters'][0]['ClusterIdentifier']
        conn.delete_cluster(myidentifier, skip_final_cluster_snapshot=False, final_cluster_snapshot_identifier=myvar)
    except:
        print "error"

def main():
    valid_args, proc = ['start','stop'], None

    # check if cmd line args were passed in (>1 as sys.argv[0] is name of program)
    if len(sys.argv) > 1:
        if sys.argv[1].lower() in valid_args:
            proc = sys.argv[1].lower()

    # if a valid arg was passed in this has been stored in proc, if not prompt user
    while not proc or proc not in valid_args:
        print "\nPlease state which procedure you want to call, valid options are:", valid_args
        proc = raw_input('>>> ').lower()

        # prompt user if invalid
        if proc not in valid_args:
            print proc, 'is not a valid selection.'

    if proc == 'start':
        start_custer()
    elif proc == 'stop':
        stop_cluster()

# this makes the script automatically call main when starting up
if __name__ == '__main__':
    main()

你可以从命令行调用它，例如如果您与文件位于同一目录中（例如名为cluster_ctrl.py）：

python cluster_ctrl.py start

从命令提示符调用函数

4 个答案: