v3.0.0 - CVE-2025-69872 fix, diskcache → cachetools

IndiaPincodeFinder v3.0.0

Security: CVE-2025-69872 addressed

This release replaces diskcache with cachetools.LRUCache to mitigate CVE-2025-69872 (CVSS 9.8). The previous diskcache dependency had its last commit over 2 years ago and used pickle-based persistence, which posed a security risk. We now use the actively maintained cachetools library with a simple in-memory cache.

What's changed

• Removed diskcache dependency
• Added cachetools>=7.0.1 as the in-memory cache backend
• Updated docstrings to reflect that the cache is in-memory (no persistence across restarts)
• Added version & stress test script (python/scripts/test_version_stress.py) for production validation

Breaking changes

• Python 3.9 no longer supported. requires-python is now >=3.10 (required by cachetools>=7.0.1)

Performance

All public APIs remain unchanged. Benchmarks on ~18.8k pincodes:

Metric	Result
Import + cache load	~0.02–0.03 s
Stress test (200k lookups, random pincodes)	~1.6M–2.45M lookups/s
Tight loop (800k lookups, single pincode)	~0.17–0.29 µs per lookup

The in-memory cache eliminates disk and pickle overhead from the previous diskcache implementation.

Upgrade

pip install --upgrade indiapincodefinder

No code changes required—the public API (pin_to_address, pin_to_state, pin_to_district, pin_to_taluka, load_pincode_data) is unchanged.