Upload code to the Robot Inventor hub

upload.py

import base64
import json
import sys
import serial
import random
import os

if len(sys.argv) != 4:
    print(f"Usage\n{sys.argv[1]} tty code.py slot")
    exit()

_, tty, path, slot = sys.argv

hub = serial.Serial(tty, 115200)

def waitfor(cmdid):
    while True:
        try:
            dat = json.loads(hub.read_until(b'\r'))
        except json.JSONDecodeError as e:
            print(e)
            continue
        print(dat)
        if dat.get('i') == cmd_id:
            return dat

### start_write_program
stat = os.stat(path)
cmd_id = base64.b64encode(random.randbytes(3)).decode()
project_id = base64.b64encode(random.randbytes(9)).decode()
dat = json.dumps({
    "i": cmd_id,
    "m": "start_write_program",
    "p": {
        "meta": {
            "created": int(stat.st_ctime),
            "modified": int(stat.st_mtime),
            "project_id": project_id,
            "name": base64.b64encode(path.encode()).decode(),
            "type": "python"},
    "size": stat.st_size,
    "slotid": int(slot)}})
print(dat)
hub.write(dat.encode() + b'\r')

dat = waitfor(cmd_id)
blocksize = dat['r']['blocksize']
transferid = dat['r']['transferid']

### write_package
with open(path, 'rb') as f:
    for chunk in iter(lambda:f.read(blocksize), b''):
        enc = base64.b64encode(chunk).decode()
        cmd_id = base64.b64encode(random.randbytes(3)).decode()
        dat = json.dumps({
            "i": cmd_id,
            "m": "write_package",
            "p": {"data": enc, "transferid": transferid}
        })
        print(dat)
        hub.write(dat.encode() + b'\r')
        dat = waitfor(cmd_id)

# wait for error
while True:
    try:
        dat = json.loads(hub.read_until(b'\r'))
    except json.JSONDecodeError as e:
        print(e)
        continue
    print(dat)
    if dat.get('m') in {"runtime_error", "user_program_error"}:
        version, key, py, err, unk = dat['p']
        print(base64.b64decode(err).decode())
        break