import pandas as pd
from datetime import datetime
def load_attendance(csv_file):
df = pd.read_csv(csv_file)
return df.groupby('student').agg({'present': 'sum', 'total': 'sum'})
def calculate_rate(row):
return (row['present'] / row['total']) * 100
result = load_attendance('attendance.csv')
result['rate'] = result.apply(calculate_rate, axis=1)
at_risk = result[result['rate'] < 75]
print(json.dumps(at_risk.index.tolist()))