双重差分基础

def solve():
    import pandas as pd
    import numpy as np
    import statsmodels.api as sm
    df = pd.read_csv(____)
    df['____'] = np.log(____)
    df['____'] = df['____'] * df['____']
    X = sm.add_constant(____)
    model = sm.OLS(____).fit()
    print(____)