[USER (data scientist)]: Hey Tapilot, I'm working on this atp_tennis dataset and I could use a hand. Can you help me figure out if there are any missing values or weird data stuff going on? Please generate a value to show the number of missing values in this dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import pickle

atp_tennis = pd.read_csv('atp_tennis.csv')

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

print(missing_values)

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: No problem, happy to help! Let's start by finding any missing values in the dataset. Here's some code for that: 
'''
import pandas as pd
import pickle

atp_tennis = pd.read_csv('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
