import pandas as pd
from datetime import datetime
def check_milestones(df):
today = datetime.now()
df['deadline'] = pd.to_datetime(df['deadline'])
df['status'] = 'On Track'
df.loc[df['deadline'] < today, 'status'] = 'Overdue'
df.loc[df['completed'] == True, 'status'] = 'Completed'
return df
thesis = pd.read_csv('thesis_tracking.csv')
result = check_milestones(thesis)
overdue = result[result['status'] == 'Overdue']
print(f'Overdue milestones: {len(overdue)}')