用for loop回答下面问题Write a python function proddigits() that inputs a positive integer number and returns the product of digits of that number. For example, if the input is 422, the function should return 16 (which is equal to 4×2×2 ).

Sure, here is the modified `proddigits()` function that uses a `for` loop to calculate the product of digits:

def proddigits(n):
    # Initialize the result
    result = 1
    
    # Convert the number to a string for iteration
    n_str = str(n)
    
    # Loop through each digit of the number
    for digit in n_str:
        # Convert the digit back to an integer
        digit_int = int(digit)
        
        # Multiply it to the result
        result *= digit_int
    
    # Return the final result
    return result

You can call this function with a positive integer argument to get the product of its digits. For example:

# Test the function
num = 422
print(proddigits(num))  # Output: 16

I hope this helps! Let me know if you have any other questions.