A parsing algorithm in python
Python can automate log analysis and security tasks by combining file handling, parsing, and algorithm development. This example demonstrates how to build a suspicious login detection algorithm to identify users with three or more failed login attempts.
Steps to Build the Algorithm
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Understand the Input: o Input Structure: A .txt log file with one username per line, where each entry represents a failed login attempt. o Goal: For every login, check the number of failed attempts for the user and return an alert if they have three or more failed attempts.
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Import and Parse the Log File: • Open the file using the open() function with the mode "r" for reading. • Use the .read() method to load the file content as a string. • Apply the .split() method to separate the string into a list of usernames. Example: with open("login_attempts.txt", "r") as file: file_content = file.read() usernames = file_content.split() # Parse file into a list of usernames
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Counting Username Occurrences: • Use a for loop to iterate over the list. • Maintain a counter variable to track how many times the target username appears. • Increment the counter each time the username matches the target. Example: counter = 0 target_user = "eraab" for user in usernames: if user == target_user: counter += 1
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Define the Function: • Create a reusable function to: o Accept a list of usernames (login_list) and the current user (current_user) as arguments. o Count occurrences of current_user in login_list. o Print an alert if the count is three or more; otherwise, allow login. Example: def login_check(login_list, current_user): counter = 0 for user in login_list: if user == current_user: counter += 1 if counter >= 3: print(f"Account locked for user: {current_user}") else: print(f"User {current_user} can log in.")
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Run the Function: • Test the function on specific usernames from the log. • Example: login_check(usernames, "elarson") # Output: User elarson can log in. login_check(usernames, "eraab") # Output: Account locked for user: eraab