Ask and ye shall receive! I'm tacking a GPL 3 license to it. The plugs that play a sound after a delay won't work on Windows because I use fork(), but I don't use Windows because fuck Windows. It uses mpv to play sounds, but that is easily changed. AMA.

#!/usr/bin/env python
"Control my various tasmota devices. Licensed under GPL v3: https://www.gnu.org/licenses/gpl-3.0.en.html#license-text"

import os
from time import sleep
import urllib.request
from json import loads
from subprocess import Popen

__all__ = ["Tasmota", "TasmotaWarmup", "TasmotaOffFirst", "DEVICENAMES"]

class Tasmota():
    "A tasmota device."
    def __init__(self, ipaddress: str, name: str=None):
        self.ipaddress = ipaddress
        self.name = name

    def __repr__(self):
        return f"<{type(self).__name__} {self.name if self.name else self.ipaddress}>"

    def _request(self, cmd: str) -> str:
        "make an http request to the device"
        return urllib.request.urlopen(f"http://{self.ipaddress}/cm?cmnd={cmd.replace(' ', '%20')}").read()

    def on(self) -> bool:
        "Turn the device on. return True if successful"
        return b"ON" in self._request("Power On")

    def off(self) -> bool:
        "Turn the device off. return True if successful"
        return b"OFF" in self._request("Power Off")

    def toggle(self) -> bool:
        "Toggle the device power. return True if power is now on, False if it's off"
        return b"ON" in self._request("Power Toggle")

    def status(self) -> bool:
        "return True if the device is on, False if it is off"
        return bool(loads(self._request("Status"))["Status"]["Power"])

class TasmotaWarmup(Tasmota):
    "Plays a sound when started, plays a sound after a waiting period."
    def __init__(self, ipaddress: str, name: str=None, warmup_time: int=None, on_sound: str=None, ready_sound: str=None):
        "warmup_time is seconds, on/ready_sound is the path to the audio file to play"
        super().__init__(ipaddress, name)
        self.warmup_time = warmup_time
        self.on_sound = on_sound
        self.ready_sound = ready_sound

    def _playSound(self, sound: str) -> None:
        "play a sound"
        Popen(["mpv", "--no-terminal", "--volume=60", sound])

    def _beginPowerOnSounds(self) -> None:
        "Play a sound when turning on and another sound when ready"
        if self.on_sound:
                self._playSound(self.on_sound)
        if self.warmup_time and self.ready_sound:
            if __name__ == "__main__": # using this as a script, fork to background and return terminal
                if os.fork() == 0: # wait in the background for the warmup_time
                    self._sleepAndPlay()
                    raise SystemExit
            else:
                Thread(target=self._sleepAndPlay).start()

    def _sleepAndPlay(self) -> None:
        "The actual sleeping and playing, to be run in a thread if needed."
        sleep(self.warmup_time)
        if self.status(): # if device is still on
            self._playSound(self.ready_sound)

    def on(self) -> bool:
        "Turn the device on and play sounds"
        if super().on():
            self._beginPowerOnSounds()
            return True
        return False

    def toggle(self) -> bool:
        "toggle the status and play sounds if we're turning it on"
        if super().toggle():
            self._beginPowerOnSounds()
            return True
        return False

class TasmotaOffFirst(TasmotaWarmup):
    "A Tasmota object that turns the device off first before turning it on"
    def _turn_off_before_on(self) -> bool:
        "Turn this device off first if it's already on when it's switched on"
        if not super().toggle(): # if toggling turned it off
            super().on()
        return True

    def on(self) -> bool:
        return self._turn_off_before_on()

class TasmotaAlwaysOn(TasmotaOffFirst):
    "This Tasmota class is always on; toggling it will turn it off briefly and then back on"
    def toggle(self) -> bool:
        "toggle this device off and then back on again"
        return self._turn_off_before_on()

DEVICENAMES = {"volcano": TasmotaWarmup("192.168.1.152", "Volcano", 355, "/home/jt/.sounds/hold up hey.ogg",
                                        "/home/jt/.sounds/fill that bag up right now2.flac"),
                   "towel": TasmotaOffFirst("192.168.1.153", "Towel Warmer", warmup_time=(20*60)+30,
                                            ready_sound="/home/jt/.sounds/yayeah.ogg"),
                   "radiator": Tasmota("192.168.1.166", "Radiator"),
                   "taco": TasmotaAlwaysOn("192.168.1.156", "Taco")
                   }

if __name__ != "__main__":
    from threading import Thread # only needed when importing this module
else:
    import sys, argparse
    parser = argparse.ArgumentParser(description="Control Tasmota wifi power plugs")
    parser.add_argument("devices", help="device(s)", action="store", nargs="*")
    operation_group = parser.add_mutually_exclusive_group()
    operation_group.add_argument('--on', '-n', help="power on device", action="store_true")
    operation_group.add_argument('--off', '-f', help="power off device", action="store_true")
    operation_group.add_argument('--toggle', '-t', help="toggle device power", action="store_true")
    operation_group.add_argument('--status', '-s', help="get status of device", action="store_true")
    args = parser.parse_args()

    # Sanity checks
    if not args.devices:
        print(f"No device specified. Available devices are: {' '.join(DEVICENAMES.keys())}", file=sys.stderr)
        parser.print_help()
        sys.exit(1)
    invalid = []
    for d in args.devices:
        if not DEVICENAMES.get(d):
            invalid.append(d)
    if invalid:
        print(f"Invalid device{'s' if len(invalid) > 1 else ''}: {' '.join(invalid)}", file=sys.stderr)
        print(f"Available devices are: {' '.join(DEVICENAMES.keys())}", file=sys.stderr)
        sys.exit(3)
    for d in args.devices: # gogo
        t = DEVICENAMES[d]
        if args.on:
            if t.on():
                print(f"{t.name} turned on")
            else:
                print(f"Failed to turn on {t.name}", file=sys.stderr)
        elif args.off:
            if t.off():
                print(f"{t.name} turned off")
            else:
                print(f"Failed to turn off {t.name}", file=sys.stderr)
        elif args.toggle:
            print(f"{t.name} turned {'on' if t.toggle() else 'off'}")
        elif args.status:
            print(f"{t.name} is {'on' if t.status() else 'off'}")