launchMultiple.py

#!/usr/bin/env python3

import iterm2
import AppKit
import asyncio

# Each command runs in its own tab.
commands = [
    "echo 1",
    "echo 2"
]

# Launch app if needed.
assert AppKit.NSWorkspace.sharedWorkspace().launchApplication_("iTerm")

async def run_cmd(window, cmd, first):
  tab = window.tabs[0] if first else await window.async_create_tab()
  await tab.sessions[0].async_send_text(cmd + '\n')

async def main(conn):
  window = await iterm2.Window.async_create(conn)
  async_tabs = (run_cmd(window, cmd, idx == 0) for idx, cmd in enumerate(commands))

  # Create tabs, send text and bring window to foreground in parallel.
  await asyncio.gather(window.async_activate(), *async_tabs)

# Passing True for the second parameter means keep trying to
# connect until the app launches.
iterm2.run_until_complete(main, True)