You want to find the index where the substring "192.168.243.140" starts within the string contained in the variable ip_addresses.

To find the index where the substring "192.168.243.140" starts within the string contained in the variable ip_addresses, we can utilize the built-in string method find() in Python. Here's the step-by-step breakdown of the solution:

Step 1: Define the Variables

1. Set the variable ip_addresses to the string of IP addresses you want to search within.
2. Define the substring you are looking for: "192.168.243.140".

Step 2: Use the find() Method

1. Call the find() method on the ip_addresses string, passing the substring as an argument.
2. This method will return the starting index of the first occurrence of the substring.

Step 3: Handle the Return Value

1. If the substring is found, it will return the index (a non-negative integer).
2. If the substring is not found, it will return -1.

Final Answer

Here is how you can implement the solution in Python:

# Example string containing multiple IP addresses
ip_addresses = "Some text... 192.168.243.140 ... more text"
substring = "192.168.243.140"

# Finding the index
index = ip_addresses.find(substring)

# The final result
print(index)  # This will print the starting index or -1 if not found

Just replace the ip_addresses string with your actual data, and running this code snippet will give you the starting index of the substring.