schema.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "minItems": 1,
  "uniqueItems": true,
  "items": {
    "type": "object",
    "properties": {
      "package_name": { "type": "string" },
      "version": {
        "type": "string",
        "_comment": "PEP404 version string prefixed with a comparison operator, Excluding trailing '.*'.\nhttps://peps.python.org/pep-0440/#version-specifiers\nhttps://peps.python.org/pep-0440/#appendix-b-parsing-version-strings-with-regular-expressions",
        "pattern": "^(~=|==|!=|<=|>=|<|>|===)\\s*([1-9][0-9]*!)?(0|[1-9][0-9]*)(\\.(0|[1-9][0-9]*))*((a|b|rc)(0|[1-9][0-9]*))?(\\.post(0|[1-9][0-9]*))?(\\.dev(0|[1-9][0-9]*))?$"
      },
      "approval_date": {
        "type": "string",
        "format": "date"
      },
      "revoke_date": {
        "oneOf": [
          {
            "type": "string",
            "format": "date"
          },
          {
            "type": "null"
          }
        ]
      }
    },
    "required": ["package_name", "version", "approval_date", "revoke_date"],
    "additionalProperties": false
  }
}