def check(self, data: Dict): for key, rule in self.rules.items(): value = data.get(key) # Required check if rule.get("required", False) and value is None: self.errors.append(f"Missing required key: key") continue if value is None: continue # Type check expected_type = rule.get("type") if expected_type and not isinstance(value, eval(expected_type.capitalize())): self.errors.append(f"Key 'key' expected expected_type, got type(value).__name__") # Pattern check pattern = rule.get("pattern") if pattern and isinstance(value, str) and not re.match(pattern, value): self.errors.append(f"Key 'key' does not match pattern: pattern") return len(self.errors) == 0

In the modern landscape of software development, data engineering, and DevOps, the integrity of data structures is paramount. One of the most fundamental yet often overlooked data models is the Key-Value (KV) store . From Redis caches to JavaScript objects, from configuration files to NoSQL databases, key-value pairs are everywhere. But how do you ensure that your data isn't corrupted, incomplete, or misconfigured? Enter the KV Checker Full —a comprehensive tool and methodology for validating every aspect of your key-value data.

| Feature | Description | Example Violation | | :--- | :--- | :--- | | | Required keys must exist. | Key api_key is missing from config. | | Absence Check | Deprecated keys must be removed. | Legacy use_v2 key still present. | | Type Enforcement | Strict type matching. | Value "123" when integer expected. | | Format Validation | Regex or semantic format checks. | email key "john@com" (missing TLD). | | Range & Limit | Numeric or length boundaries. | page_size = 1000 when max is 100 . | | Uniqueness | Duplicate keys flagged (in arrays of KV pairs). | Two identical id keys in one block. | | Nesting Depth | Prevents overly complex nested structures. | Object nested 20 levels deep. | How to Perform a Full KV Check: Step-by-Step Workflow Whether you use an off-the-shelf tool or a custom script, a rigorous KV check follows this logical flow: Step 1: Parse the Source Load the KV data from your source—this could be a JSON file, a YAML configuration, a .env file, or a direct connection to Redis or Memcached. The parser must be fault-tolerant but strict enough to catch syntax errors. Step 2: Flatten Nested Structures (If Needed) Many KV checkers transform nested objects into dot-notation paths. For example:

import json import re from typing import Any, Dict, List class KVCheckerFull: def (self, rules: Dict): self.rules = rules # Expects dict: "key_name": "type": str, "required": bool, "pattern": str self.errors = []