Check tello wifi connection and get current battery.

tello_get_battery.py

import subprocess
import time
import pywifi
from pywifi import const
import socket
import threading

"""
Global variable
"""
# Setting tello SSID
targetSSID = 'TELLO-A0502E'
# UDP socket setting
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.bind(('', 9000))

def main():
  # WiFi connection
  result = checkWiFi()
  if(result):
    print('connected!')
    # Create socket thread listening 9000 PORT form tello
    recvThread = threading.Thread(target=recv)
    recvThread.start()
    # send command message to tello by UDP socket
    sock.sendto(("command").encode(encoding='utf-8'), ('192.168.10.1', 8889))
    sock.sendto(("battery?").encode(encoding='utf-8'), ('192.168.10.1', 8889))
    time.sleep(1)
    sock.close()
  else:
    print('connect failed!')
  
"""
WiFi connection
"""
def checkWiFi():
  wifi_SSID = get_wifi_info_win()["SSID"]
  print(f"[1] Current WiFi Network: {wifi_SSID}")
  if(wifi_SSID != targetSSID):
    # 獲取網卡介面
    wifi = pywifi.PyWiFi()
    # 得到第一個無線網卡
    iface = wifi.interfaces()[0]
    iface.disconnect()
    # create wifi connection
    profile = pywifi.Profile()
    profile.ssid = targetSSID
    profile.auth = const.AUTH_ALG_OPEN
    profile.akm.append(const.AKM_TYPE_WPA2PSK)
    profile.cipher = const.CIPHER_TYPE_CCMP
    profile.key = '' # password
    # 洗掉已連接的所有wifi檔案
    iface.remove_all_network_profiles()
    # 加載新的wifi連接檔案
    tep_profile = iface.add_network_profile(profile)
    #  連接上面的wifi檔案
    iface.connect(tep_profile)
    time.sleep(1)
    # 如果wifi已連接
    wifi_SSID = get_wifi_info_win()["SSID"]
    print(f"[2] Current WiFi Network: {wifi_SSID}")
    if(wifi_SSID != targetSSID):
      return False
    else:
      return True
  else:
    return True

"""
Threading listening 9000 PORT form tello
"""
def recv():
    while True:
        try:
            data, server = sock.recvfrom(1024)
            print("{} : {}".format(server, data.decode(encoding="utf-8")))
        except Exception:
            print('\nExit . . .\n')
            sock.close()
            break

"""
Get Wifi information on Mac OSx
"""
def get_wifi_info_mac():
	process = subprocess.Popen(['/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport','-I'], stdout=subprocess.PIPE)
	out, err = process.communicate()
	process.wait()

	wifi_info = {}
	for line in out.decode("utf-8").split("\n"):
		if ": " in line:
			key, val = line.split(": ")
			key = key.replace(" ", "")
			val = val.strip()

			wifi_info[key] = val

	return wifi_info

"""
Get Wifi information on windows
"""
def get_wifi_info_win():
  out = subprocess.check_output('netsh wlan show interfaces')
  wifi_info = {}
  for line in out.decode("utf-8", errors="ignore").split("\n"):
    if ": " in line:
      key, val = line.split(": ")
      key = key.replace(" ", "")
      val = val.strip()

      wifi_info[key] = val
  return wifi_info


if __name__ == '__main__':
    main()

dependency

pywifi provides a cross-platform Python module for manipulating wireless interfaces.
install packages: pywifi

pip install pywifi

If you are mac user check here for more info.