def close(self): self.conn.close() | Problem | Strategy | |---------|----------| | Network failure | Retry with backoff (3–5 attempts) | | Rate limiting | Parse Retry-After header, queue commands | | Invalid token | Re‑authenticate automatically once | | Data gaps | Interpolate or flag missing samples | | Meter offline | Cache commands; apply when reconnected |
def fetch_latest(self): resp = self.session.get(f"self.api_root/meters/self.meter_id/reading") resp.raise_for_status() data = resp.json() # Cache it self.conn.execute( "INSERT OR REPLACE INTO readings (ts, power_w, cumulative_wh) VALUES (?, ?, ?)", (datetime.now(timezone.utc).isoformat(), data["power_w"], data["cumulative_wh"]) ) self.conn.commit() return data energyclient
def control_load(self, state: bool): """Turn load on/off (demand response)""" resp = self.session.post( f"self.api_root/meters/self.meter_id/control", json="load_control": state ) return resp.status_code == 200 def close(self): self
import requests import sqlite3 import time from dataclasses import dataclass from datetime import datetime, timezone @dataclass class EnergyClient: api_root: str meter_id: str token: str cumulative_wh) VALUES (?
def _init_db(self): self.conn = sqlite3.connect("energy_cache.db") self.conn.execute(""" CREATE TABLE IF NOT EXISTS readings ( ts TEXT PRIMARY KEY, power_w REAL, cumulative_wh REAL ) """)
"timestamp": "2025-03-15T10:00:00Z", "device_id": "meter_001", "measurements": "power_w": 1243.5, "energy_wh_cumulative": 1203400, "voltage_v": 239.2, "current_a": 5.2, "frequency_hz": 50.02 , "tariff": "off_peak"