[USER (data scientist)]: Cool, now let's calculate the range for each of those numerical columns. Please generate a dictionary that contains the range of values for each numerical column in 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("ranges:\n", ranges) 

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: You got it! You can use a for loop to iterate through the numerical columns and calculate the range. Here's the code:
'''
import pandas as pd 
import pickle
 
# Load the dataset 
credit_customers = pd.read_csv("credit_customers.csv") 
 
# YOUR SOLUTION BEGIN:
