[USER (data scientist)]: Now, let's do an ANOVA test to see if there are any big differences in the average win/loss ratios between the court surfaces. Please generate the code with the output in class type.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import scipy.stats as stats
import pickle
from decision_company import read_csv_file, df_copy, dropna, get_dummies, corr, f_oneway, avg, sem, t_ppf

atp_tennis = read_csv_file('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
<code1>
[GENERATE YOUR CODE] 
</code1>
# YOUR SOLUTION END

print(anova_result_clean)

# save data
pickle.dump(anova_result_clean,open("./pred_result/anova_result_clean.pkl","wb"))

---END CODE TEMPLATE---

[YOU (AI assistant)]: You got it! Here's the code to run the ANOVA test: 

# MY SOLUTION BEGIN:
