Raspberry Pi OS でWi-Fiが有効かを確認する

wifi_check.py

# coding: UTF-8
import subprocess
import re

def extract_essid(line):
    # ESSID:"essid" のパターンがあるかどうか
    pattern = r'.*ESSID:"(.*)"'
    result = re.match(pattern, line)
    if result:
        return (True, result.group(1))
    else:
        return (False, 'No ESSID')

def main():
    ps = subprocess.Popen(['iwconfig'], stdout = subprocess.PIPE, stderr = subprocess.STDOUT)
    try:
        output = subprocess.check_output(('grep', 'ESSID'), stdin = ps.stdout)
        result = extract_essid(output.decode())
        if result[0]:
            print('OK ' + result[1])
        else:
            print('NG ' + result[1])
    except subprocess.CalledProcessError:
        print('No Wi-Fi connected.')

if __name__ == "__main__":
    main()