1. import re
  2. import logging
  3. import os
  4. from datetime import datetime
  6. # Configure logging
  7. logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
  9. def transform_log_data(log_file_path, output_file_path, transform_function):
  10. """
  11. Transforms data from a log file and writes it to an output file.
  12. Handles potential errors gracefully.
  14. Args:
  15. log_file_path (str): Path to the input log file.
  16. output_file_path (str): Path to the output file.
  17. transform_function (callable): A function that takes a log line as input
  18. and returns the transformed data.
  19. """
  20. try:
  21. with open(log_file_path, 'r') as infile, open(output_file_path, 'w') as outfile:
  22. for line in infile:
  23. try:
  24. # Apply the transformation function
  25. transformed_data = transform_function(line)
  26. if transformed_data: # Only write if transformation was successful
  27. outfile.write(transformed_data + '\n')
  28. except Exception as e:
  29. logging.error(f"Error processing line: {line.strip()} - {e}")
  30. except FileNotFoundError:
  31. logging.error(f"Log file not found: {log_file_path}")
  32. except Exception as e:
  33. logging.error(f"An unexpected error occurred: {e}")
  37. def example_transform(log_line):
  38. """
  39. Example transformation function. Extracts timestamp and message.
  41. Args:
  42. log_line (str): A single line from the log file.
  44. Returns:
  45. str: The transformed data (timestamp, message) or None if transformation fails.
  46. """
  47. try:
  48. # Example regex to extract timestamp and message
  49. match = re.match(r'(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}).*?(?=\n|$)', log_line)
  50. if match:
  51. timestamp = match.group(1)
  52. message = match.group(0).replace(timestamp, "").strip()
  53. return f"{timestamp}, {message}"
  54. else:
  55. return None # Indicate failure
  56. except Exception as e:
  57. logging.error(f"Error in example transform: {e}")
  58. return None
  62. if __name__ == '__main__':
  63. #Example usage
  64. log_file = 'input.log'
  65. output_file = 'output.txt'
  67. # Create a dummy input log file for testing
  68. with open(log_file, 'w') as f:
  69. f.write("2023-10-27 10:00:00 This is a log message.\n")
  70. f.write("2023-10-27 10:00:05 Another log message.\n")
  71. f.write("Invalid log line\n") #Example of an invalid line.
  72. f.write("2023-10-27 10:00:10 Final log message.\n")
  74. transform_log_data(log_file, output_file, example_transform)
  76. logging.info(f"Data transformation complete. Output written to {output_file}")

Add your comment