TypeError： 只能将 str (不是 "NoneType" ) 连接到 str python boto3

Question

我已经写下了python boto3脚本来读取json文件。在读取json文件时，我使用argparse添加了一些参数。在调用脚本时，它抛出了以下错误：

这是代码

#!/usr/bin/env python
import json
import sys
import os
import re
import boto3
import argparse
def init():
global pa
parser = argparse.ArgumentParser(description='Additional Params.')
parser.add_argument('--Tier', nargs='?', dest='Tier', required=False, help='Tier')
parser.add_argument('--BusinessUnit', nargs='?', dest='BusinessUnit', required=False, help='BusinessUnit')
parser.add_argument('--LineOfBusiness', nargs='?', dest='LineOfBusiness', required=False, help='LineOfBusiness')
parser.add_argument('--branchName', nargs='?', dest='branchName', required=False, help='branchName')
parser.add_argument('--ProjectName', nargs='?', dest='ProjectName', required=False, help='ProjectName')
parser.add_argument('--ContextPath', nargs='?', dest='ContextPath', required=False, help='ContextPath')
pa = parser.parse_args()

def update_secret():
init()
with open('application-' + pa.Tier + '.properties.json') as f:
baselist = json.load(f)
client = boto3.client('secretsmanager', region_name='us-east-1')
config_secret = get_secret()
for secrets in baselist:
response = client.update_secret(SecretId=pa.BusinessUnit + "/" + pa.LineOfBusiness + "/" + pa.ProjectName + "/" + pa.branchName + pa.ContextPath + "/" + 'application_' + pa.Tier, SecretString=baselist[secrets][1:])
print(response)
if __name__ == '__main__':
update_secret()

[Container] 2020/11/09 20:13:46 Running command python updateSecrets.py --Tier $Tier --BusinessUnit $BusinessUnit --LineOfBusiness $LineOfBusiness --ProjectName ProjectName --ContextPath $ContextPath --branchName $branchName
Traceback (most recent call last):
File "updateSecrets.py", line 81, in <module>
update_secret()
File "updateSecrets.py", line 30, in update_secret
with open('application-' + pa.Tier + '.properties.json') as f:
TypeError: can only concatenate str (not "NoneType") to str

Answer 1

在传递命令行参数时，不要对值使用'$'符号。$不需要。以下是我为测试编写的最低代码。

#!/usr/bin/env python
import argparse
def init():
global pa
parser = argparse.ArgumentParser(description='Additional Params.')
parser.add_argument('--Tier', nargs='?', dest='Tier', required=False, help='Tier')
pa = parser.parse_args()

def update_secret():
init()
print('application-' + pa.Tier + '.properties.json')
if __name__ == '__main__':
update_secret()

运行上面的程序，命令行参数如下。

python3 test.py --Tier abc

它在输出下方打印

application-abc.properties.json

Answer 2

您正试图将字符串与具有None值的变量连接起来

with open('application-' + pa.Tier + '.properties.json') as f:
# pa.Tier returns None here