Files
kingchenc 5a4cf66022 examples: add streaming demos for Python and Rust
Python and Rust both lacked a standalone "streaming indicators" example
that mirrors examples/node/streaming.js — the quickstart docs cover the
pattern, but a runnable file makes the parity visible across all four
languages.

* examples/python/streaming.py — argparse-driven synthetic streaming demo
  feeding SMA(20) / EMA(20) / RSI(14) / MACD(12,26,9), tagging BUY?/SELL?
  candidates when RSI extremes and MACD-histogram direction agree.
* examples/rust/src/bin/streaming.rs — same demo as a wickra-examples
  binary, reusing the seeded LCG so its first 40 rows are bit-identical
  to the Python (and Node) sibling — a strong cross-language consistency
  signal verified by running both side by side.
* examples/README.md gains a `streaming` row in the Rust and Python tables.
2026-05-23 00:13:38 +02:00

102 lines
2.9 KiB
Python

"""Streaming indicators with the Wickra Python binding.
Feeds a synthetic price series through several indicators tick by tick — the
same O(1)-per-update model a live trading bot would use — and prints a status
line whenever every indicator has warmed up. The Python counterpart of
``examples/node/streaming.js`` and ``examples/rust/src/bin/streaming.rs``.
Run with::
python -m examples.python.streaming
"""
from __future__ import annotations
import argparse
import math
import wickra as ta
def make_series(n: int) -> list[float]:
"""Deterministic synthetic series: slow trend + two oscillations + tiny noise.
The seeded linear-congruential generator matches the Node sibling example
so a side-by-side run produces visibly comparable streams.
"""
seed = 1234567
prices: list[float] = []
for t in range(n):
seed = (seed * 1103515245 + 12345) & 0x7FFFFFFF
rand = seed / 0x7FFFFFFF
price = (
100.0
+ t * 0.05
+ math.sin(t * 0.07) * 8.0
+ math.cos(t * 0.21) * 3.0
+ (rand - 0.5)
)
prices.append(price)
return prices
def fmt(value: float | None) -> str:
if value is None:
return " -- "
if isinstance(value, float) and math.isnan(value):
return " -- "
return f"{value:7.2f}"
def main() -> int:
parser = argparse.ArgumentParser(
description=__doc__.splitlines()[0] if __doc__ else None,
)
parser.add_argument(
"--ticks",
type=int,
default=120,
help="number of synthetic price ticks to stream (default: 120)",
)
args = parser.parse_args()
if args.ticks <= 0:
parser.error("--ticks must be positive")
print(f"Wickra {ta.__version__} — streaming indicator demo (Python)\n")
sma = ta.SMA(20)
ema = ta.EMA(20)
rsi = ta.RSI(14)
macd = ta.MACD(12, 26, 9)
prices = make_series(args.ticks)
signals = 0
for t, price in enumerate(prices):
sma_v = sma.update(price)
ema_v = ema.update(price)
rsi_v = rsi.update(price)
macd_v = macd.update(price) # (macd, signal, histogram) or None
# Only act once every indicator has produced a value.
if sma_v is None or ema_v is None or rsi_v is None or macd_v is None:
continue
_macd_line, _signal, histogram = macd_v
overbought = rsi_v > 70 and histogram < 0
oversold = rsi_v < 30 and histogram > 0
tag = "SELL?" if overbought else "BUY? " if oversold else " "
if overbought or oversold:
signals += 1
print(
f"t={t:>3} price={fmt(price)} sma={fmt(sma_v)} ema={fmt(ema_v)} "
f"rsi={fmt(rsi_v)} macd_hist={fmt(histogram)} {tag}"
)
print(f"\nDone — {signals} candidate signal(s) over {len(prices)} ticks.")
return 0
if __name__ == "__main__":
raise SystemExit(main())