ID On-air ของผู้ประกาศ FM 4nsa คืออะไร?
What is the On-air ID of FM broadcaster 4nsa?
df = pd.DataFrame(columns=['on_air_id', 'band', 'callsign'])
df[(df['callsign'] == '4nsa') & (df['band'] == 'fm')]['on_air_id'].values[0]