卡方检验方差是否等于12

def solve():
    import pandas as pd
    import numpy as np
    import matplotlib.pyplot as plt
    from scipy.stats import chi2
    url = '____'
    df = pd.read_csv(____)
    n, s2 = len(____), df['____'].var()
    c = (____)*s2/____
    lo, hi = chi2.ppf(____,n-____), chi2.ppf(____,n-____)
    print(____)
    print(____)
    x = np.linspace(chi2.ppf(____,n-____), chi2.ppf(____,n-____), ____)
    plt.plot(x, chi2.pdf(____), '____', lw=____)
    plt.axvline(____); plt.axvline(____)
    plt.axvline(____)
    plt.fill_between(x, chi2.pdf(____), where=(____)|(____), alpha=____, color='____')
    plt.xlabel(____); plt.ylabel(____); plt.title(____); plt.legend()
    plt.tight_layout(); plt.show()