Python 中的多行字符串替换答案

【问题标题】：Multiline string substitution in PythonPython 中的多行字符串替换
【发布时间】：2023-02-23 09:32:41
【问题描述】：

我正在尝试这个：

account = "11111111111"
tenant_name= "Demo"
project_name= "demo"

sns_access_policy = """{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "0",
      "Effect": "Allow",
      "Principal": {
        "Service": "codestar-notifications.amazonaws.com"
      },
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:eu-west-1:{account_id}:{tenant_name}-{project_name}-pipeline-monitoring"
    }
  ]
}"""

sns_access_policy = sns_access_policy.replace("{account_id}",account).replace("{tenant_name}",tenant_name).replace("{project_name}",project_name)

这是我的工作，但我正在寻找类似f{string_substitution}的东西：

sns_access_policy = f"""{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "0",
      "Effect": "Allow",
      "Principal": {
        "Service": "codestar-notifications.amazonaws.com"
      },
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:eu-west-1:{account}:{tenant_name}-{project_name}-pipeline-monitoring"
    }
  ]
}"""

我收到以下错误：

SyntaxError: f-string: expressions nested too deeply

除了使用 .replace() 之外还有其他方法吗？

【问题讨论】：

标签： python

【解决方案1】：

当您使用 f 字符串时，所有这些大括号都会开始一个表达式，但在您的情况下，它们只是文字大括号。你必须为此使用双括号。

sns_access_policy = f"""{{
  "Version": "2012-10-17",
  "Statement": [
    {{
      "Sid": "0",
      "Effect": "Allow",
      "Principal": {{
        "Service": "codestar-notifications.amazonaws.com"
      }},
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:eu-west-1:{account}:{tenant_name}-{project_name}-pipeline-monitoring"
    }}
  ]
}}"""

【讨论】：