[USER (data scientist)]: Cool! Now, I'd like to know how many matches each player played. Can you help me with that? Please generate and display a Series showing the number of matches played on grass surfaces by each of the top 10 ranked players in the ATP tennis dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import numpy as np
import pickle
from decision_company import read_csv_file,

# please import the necessary private functions from decision_company first

atp_tennis = read_csv_file('atp_tennis.csv')

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

print(matches_played)

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: Sure thing! We can count the occurrences of each player in the 'Player_1' and 'Player_2' columns and add them up. Here's how:
'''
import pandas as pd
import numpy as np
import pickle
from decision_company import read_csv_file,

# please import the necessary private functions from decision_company first

atp_tennis = read_csv_file('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
