Credit card number redacting script

[Drone4four]

Happy New Year Pythonistas!

I’m writing a Python shell script for fun. The purpose of the script is to ask the user for a fake credit card number (16 integers) and then returns a credit card number with the first 12 integer redacted with x’s.

I’m using a for loop with enumerate. I’m making a rookie mistake. I need some guidance.

Here is my script so far:

def ccredact(string):
   '''
   Take string input and then redact first 12 of 16 numbers
   '''
   spliced_list = list(string) # Convert string to list of numbers
  
   for index, value in enumerate(spliced_list):       
       # print(index, value) # test enumerate
       index[0:13] = value = 'x'
       result = spliced_list
       return result

string = str(input("Enter your fake credit card number: "))  # input something like 1234567812345678

ccredact(string)

if __name__ == "__main__":
   pass

In this script I define the function. In this function I first describe the functionality in a doc string. Then I splice the string of numbers into a list of numbers. Then I initiate the for loop using two variables (index and value) using enumerate. Then within the loop I try to re-assign the value of the first 12 integers to ‘x’ (this line is obviously my problem area, described below). After defining the function, I then name the string variable as I prompt the user to enter their fake 16 digit credit card number. Finally, I call the string.

Here is the output:

Error:
$ python script.py
Enter your fake credit card number: 1234
Traceback (most recent call last):
  File "script.py", line 15, in <module>
    ccredact(string)
  File "script.py", line 9, in ccredact
    index[0:13] = value = 'x'
TypeError: 'int' object does not support item assignment

The traceback is drawing my attention to line 9. I see two issues. The first is index and value are integers yet I am trying to assign an ‘x’ which is a string character. Though I’m not sure how to remedy this. The second issue at this line is that Python doesn’t support three variable assignments on a single line. I am not sure how to remedy this either. What would you people recommend? Any hints?