triplehelix.py

triplehelix.py

import datetime
import json
import os
import sys

import requests


apiKey = ""
stationID = ""
weatherUnits = ""

rainfallLog = "rainfallLog.csv"
lastTotalLog = "lastTotal"
now = datetime.datetime.now().time()


def calc(precipTotal):
    if now.hour == 0:
        lastTotal = 0.0
    else:
        with open(lastTotalLog, "r") as f:
            lastTotal = float(f.readline())
    return round(precipTotal - lastTotal, 2)


def create_empty_files():
    if not os.path.isfile(lastTotalLog):
        with open(lastTotalLog, "w") as f:
            f.write("0")
    if not os.path.isfile(rainfallLog):
        with open(rainfallLog, "w") as f:
            f.write("Time,Hourly Rainfall (mm)\n")


def get_weather_data_from_api():
    r = requests.get(
        f"https://api.weather.com/v2/pws/observations/current?stationId={stationID}8&format=json&units={weatherUnits}&apiKey={apiKey}"
    )
    r.raise_for_status()
    return json.loads(r.text)


if __name__ == "__main__":
    create_empty_files()
    try:
        weather = get_weather_data_from_api()
    except requests.RequestException as e:
        print(e)
        sys.exit(1)
    
    dataTime = weather["observations"][0]["obsTimeLocal"]
    precipTotal = weather["observations"][0]["uk_hybrid"]["precipTotal"]

    if weatherUnits == "h":
        precipTotal *= 25.4  # API bug shows inch so convert to mm

    hourlyRain = calc(precipTotal)
    with open(rainfallLog, "a") as f:
        f.write(f"{dataTime},{hourlyRain}\n")

    with open(lastTotalLog, "w") as f:
        f.write(precipTotal)

triplehelix2.py

import datetime
import json
import os
from http.client import HTTPSConnection


API_KEY = ""
STATION_ID = ""
WEATHER_UNITS = "h"
CSV = "rainfall.csv"


def calc(current_value, last_value):
    if current_value == 0 or last_value == 0:
        return current_value

    return round(last_value - current_value, 2)


def create_empty_files():
    if os.path.exists(CSV):
        return

    one_hour_before = (
        datetime.datetime.utcnow() - datetime.timedelta(hours=1)
    ).isoformat()
    with open(CSV, "w") as f:
        f.write("Time,Hourly Rainfall (mm)\n")
        f.write(f"{one_hour_before},0.0\n")


def write_data(data):
    dt = datetime.datetime.utcnow().isoformat()
    with open(CSV, "a") as f:
        f.write(f"{dt},{data}\n")


def get_last_entry():
    with open(CSV) as f:
            l = f.readlines()[-1].strip()
    return float(l.partition(",")[2])


# API Call
def get_weather_data_from_api():
    conn = HTTPSConnection("api.weather.com")
    conn.request(
        "GET",
        f"/v2/pws/observations/current?stationId={STATION_ID}&format=json&units={WEATHER_UNITS}&apiKey={API_KEY}"
    )
    r = conn.getresponse()
    return json.loads(r.read())["observations"][0]


if __name__ == "__main__": # The main routine
    create_empty_files()
    last_entry = get_last_entry()
    try:
        data = get_weather_data_from_api()
        precipitation = calc(
            float(data["uk_hybrid"]["precipTotal"]), last_entry
        )
        write_data(precipitation)
    except (OSError, json.JSONDecodeError) as e:
        print(e)

Most programming language allows you to return early from a function if a condition isn't met tbh. Sometimes it just looks odd or people don't think about doing it that way and wrap it in an else for no real gain.