[USER (data scientist)]: Great, that's what I needed! Now, I want to make a list of nominal categorical columns from those variables. Can you help me with that? Please generate a list of nominal categorical columns from the dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd 
import pickle
 
# Load the dataset 
credit_customers = pd.read_csv("credit_customers.csv") 
 
# YOUR SOLUTION BEGIN:
<code1>
[COMPLETE YOUR CODE] 
</code1>
# YOUR SOLUTION END

print("nominal_categorical_columns:\n", nominal_categorical_columns) 

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: Sure thing! Here's the code to create a list of nominal categorical columns:
'''
import pandas as pd 
import pickle
 
# Load the dataset 
credit_customers = pd.read_csv("credit_customers.csv") 
 
# YOUR SOLUTION BEGIN:
