接受在 shell 中输入的参数的 Python 脚本出现错误

Question

我正在开发一个脚本来自动创建 mysql 数据库和数据库的用户创建。它接受在 shell 中输入的参数 -o -dp -dr 使用以下参数（-o 和 -dp）创建 sql 脚本并使用 root 密码（-dr）执行该脚本

from sys import argv
from os import makedirs,system
etc = '/mnt/storage/'
def show_usage():
    print("""
        Create new DB and DB user
        -o object_name
        -dp db user password
        -dr mysql root user password
        """)
    exit(1)

def create_template(object_name, password):
    out = """
            %s template %s example %s %s %s %s
           """%(object_name,object_name,password,object_name,object_name)
    return out

def write_to_sql(object_name, db_password):
    sql_script = open(etc+'new_db_and_user.sql','w+')
    script_to_write = create_template(object_name,db_password)
    sql_script.write(script_to_write)

def execute_sql_script(root_password):
    run_sql_script = "mysql --username=root --password=%s < new_db_and_user.sql"%(root_password)
    remove_sql_script = "rm -f new_db_and_user.sql"
    system(run_sql_script)
    system(remove_sql_script)

try:
    opts, args = getopt.getopt(argv[1:], "hd:s:", ["object_name=","db_password=", "root_password="])
except getopt.GetoptError as err:
    print(str(err))

if opts.__len__() == 0:
    show_usage()

object_name=None
password=None
root_password=None

for option, value in opts:
    if option in ('-o', '--object_name'):
        object_name = value
    elif option in ('-dp', '--db_password'):
        password = value
    elif option in ('-dr', '--root_password'):
        root_password = value
    else:
        print("Unknown parameter used")
        show_usage()


write_to_sql(object_name,password)
execute_sql_script(root_password)

问题

当我使用以下命令执行此脚本时

python create_db.py -o test -dp papa -dr nana

我收到一条错误消息：

option -o not recognized
Traceback (most recent call last):
  File "create_db.py", line 43, in <module>
    if opts.__len__() == 0:
NameError: name 'opts' is not defined

你能帮帮我吗？

Answer 1

当你在输出中得到这个时，

option -o not recognized

表示这一行

opts, args = getopt.getopt(argv[1:], "hd:s:", ["object_name=","db_password=", "root_password="])

失败了。所以执行落入异常处理程序

except getopt.GetoptError as err:
    print(str(err))

因此根本没有创建变量opts。

您可以通过首先在opts, args = ... 行之前定义变量来轻松修复它。例如

try:
    opts = []  # Define the variable opts
    opts, args = getopt.getopt(argv[1:], "hd:s:", ["object_name=","db_password=", "root_password="])
except getopt.GetoptError as err:
    print(str(err))