Correlation_function_python

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import scipy.stats
from statsmodels.graphics.tsaplots import plot_acf
import scipy
import spectrochempy as scp
#https://scicoding.com/4-ways-of-calculating-autocorrelation-in-python/
if __name__ == '__main__':
    df = pd.read_csv('CompanyABCProfit.csv').set_index('Year')
    fig = plt.figure(figsize=(10, 10))
    plt.xlabel('Year')
    plt.ylabel('Profit')
    # df.plot()
    # plt.close()
    values_df = []
    for value in df["Profit(Rs '000)"]:
        values_df.append(value)
    corr_func = (np.correlate(values_df - df.mean()[0], values_df - df.mean()[0], 'full')) / df.var()[0] / len(values_df)
    fig = plt.figure(figsize=(10, 10))
    corr_function = pd.DataFrame(corr_func).reset_index()
    corr_function['index'] = corr_function['index'] - len(df)
    corr_function = corr_function.set_index('index')
    corr_function.plot()
    plt.show()