nzpy-extended 0.0.1

IBM Netezza python driver - extended fork

nzpy_extended: High-performance IBM Netezza driver for Python

nzpy_extended is a hard fork of IBM nzpy — enriched with new features, major performance improvements via a C extension, and expanded platform support.

Key differences from upstream nzpy

Feature	nzpy (IBM)	nzpy_extended
Row parsing performance	~13 000 rows/s (pure Python)	~50 000 rows/s (optimized Python) → ~200 000 rows/s (+ C ext, exceeds ODBC ~160 k)
Supported Python	3.5+	3.12, 3.13, 3.14
Platform wheels	❌ None	✅ Linux x64, macOS ARM, Windows x64 (pre-built)
Async support	❌	✅ Fully async API

A large portion of the speedup comes from avoiding unnecessary object allocations in pure Python (~13 k → ~50 k rows/s). When the C extension is available (_HAVE_C_EXT = True), parsing of integers, floats, decimals, dates, times, timestamps, booleans, and strings all happen in native C — avoiding Python object allocations per field and struct.unpack overhead — boosting throughput to ~200 k rows/s.

If the compiled extension is not available (unsupported platform or Python version), the driver gracefully falls back to pure Python with identical semantics.

Installation

pip install nzpy_extended

Pre-built wheels are provided for:

Platform	Architecture	Python
Linux	x86_64 (manylinux)	3.12 / 3.13 / 3.14
macOS	ARM64 (Apple Silicon)	3.12 / 3.13 / 3.14
Windows	x86_64	3.12 / 3.13 / 3.14

For other platforms or Python versions, pip install will compile the C extension from source (requires a C compiler: GCC, Clang, or MSVC). On systems without a compiler the install will fail — use a supported platform or version.

Quick start

import nzpy_extended as nzpy

conn = nzpy.connect(
    user="admin", password="password",
    host="localhost", port=5480, database="db1",
    securityLevel=1,
)

with conn.cursor() as cursor:
    cursor.execute("CREATE TABLE IF NOT EXISTS test (id INT, name VARCHAR(50))")
    cursor.execute("INSERT INTO test VALUES (?, ?)", (1, "Alice"))
    cursor.execute("SELECT * FROM test")
    rows = cursor.fetchall()
    for row in rows:
        print(row)

Requirements

• Python ≥ 3.12
• CPython (PyPy not supported for C extension, pure-Python fallback only)

Documentation

• GitHub Wiki
• Issue tracker

Testing

Running the test suite

Tests require a running Netezza instance. Set the connection environment variables:

export NZ_DEV_HOST=your_netezza_host
export NZ_DEV_PORT=5480
export NZ_DEV_DB=JUST_DATA
export NZ_DEV_USER=admin
export NZ_DEV_PASSWORD=password

Run all tests:

pytest tests/ -v

C Extension / Pure Python parity

The C extension and pure-Python fallback must produce identical results for all data types. Parity tests verify this in two ways:

Unit tests (tests/test_c_python_parity_unit.py) — compare individual C parser functions against Python reference implementations byte-by-byte. No database required.

pytest tests/test_c_python_parity_unit.py -v

Integration tests (tests/test_c_python_parity_integration.py) — run real SQL queries through both code paths and verify results match. Requires a database.

pytest tests/test_c_python_parity_integration.py -v

Verification script — runs both test suites in C-extension and pure-Python modes side-by-side:

python tools/verify_c_python_parity.py

Disabling C extension at runtime:

Set the environment variable NZPY_EXTENDED_NO_CEXT=1 to force pure-Python mode even when the compiled extension is available. Useful for debugging or verifying fallback correctness.

NZPY_EXTENDED_NO_CEXT=1 pip install nzpy_extended
# or at runtime:
NZPY_EXTENDED_NO_CEXT=1 python -c "import nzpy_extended.core; print(nzpy_extended.core._HAVE_C_EXT)"  # False

License

Apache License 2.0 — see LICENSE.