[USER (data scientist)]: Hey Tapilot, I've got this dataset called "credit_customers.csv" and I need to preprocess it for a machine learning model. Can you help me load it using pandas? 

[YOU (AI assistant)]: Absolutely! Here's the code to load your dataset using proper functions from decision_company like this:

'''
import pandas as pd   
import pickle
from decision_company import read_csv_file

# Load the dataset  
credit_customers = read_csv_file("credit_customers.csv")  
'''

[USER (data scientist)]: Awesome, thanks! Now, I need to figure out which variables are categorical. Can you help me with that? Please generate the code with the output in index type.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd  
import pickle
from decision_company import read_csv_file, select_data_types, get_columns

# Load the dataset  
credit_customers = read_csv_file("credit_customers.csv")  
  
# YOUR SOLUTION BEGIN:
<code1>
[GENERATE YOUR CODE]  
</code1>
# YOUR SOLUTION END

print("categorical_columns:\n", categorical_columns)    

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: Of course! Here's the code to identify the categorical variables in your dataset:

# MY SOLUTION BEGIN:
