dishwasher.py

#!/usr/bin/python3

import json
import urllib.request
import time
from calendar import timegm

import platform
if platform.uname().machine[0:6] == "iPhone":
    import console
    console.clear()


def add_next(n, l):
    if len(l) < n:
        return None
    if n < 1:
        return (0, 0)
    return (l[0][0] + add_next(n - 1, l[1:])[0], l[0][1])


url = 'https://api.octopus.energy/v1/products/AGILE-18-02-21/electricity-tariffs/E-1R-AGILE-18-02-21-A/standard-unit-rates/'

try:
    with urllib.request.urlopen(url, timeout=30) as u:
        data = u.read()
except:
    print("Couldn't read data from {}.".format(url))
    exit()

try:
    decoded_data = json.loads(data.decode('utf-8'))
except:
    print("Webserver didn't return valid JSON")
    exit()

now = time.time()
prices = [(x['value_inc_vat'], timegm(time.strptime(x['valid_from'],
                                                     '%Y-%m-%dT%H:%M:%SZ')))
          for x in decoded_data['results']]
future_prices = [x for x in prices if x[1] > now]

future_prices.sort(key=lambda x: x[1])

three_hour_prices = []
for x in range(len(future_prices)):
    thp = add_next(6, future_prices[x:])
    if thp is not None:
        three_hour_prices.append((round(thp[0] / 6, 2), thp[1]))

three_hour_prices.sort(key=lambda x: x[0])

avg_price, start_time = (three_hour_prices[0][0],
                         time.localtime(three_hour_prices[0][1]))
print(f"Cheapest 3 hours starts at {start_time.tm_hour:02}:{start_time.tm_min:02}\nwith an average price of {avg_price} pence per kilowatt hour.")