1. import re
  2. import csv
  4. def transform_file(input_filepath, output_filepath, transform_function):
  5. """
  6. Transforms data in a file using a provided function.
  8. Args:
  9. input_filepath (str): Path to the input file.
  10. output_filepath (str): Path to the output file.
  11. transform_function (callable): Function to apply to each line of data.
  12. Takes a single line (str) as input and returns the transformed line (str).
  13. """
  14. try:
  15. with open(input_filepath, 'r', encoding='utf-8') as infile, \
  16. open(output_filepath, 'w', encoding='utf-8') as outfile:
  18. # Iterate through each line in the input file
  19. for line in infile:
  20. # Apply the transformation function to the current line
  21. transformed_line = transform_function(line)
  22. # Write the transformed line to the output file
  23. outfile.write(transformed_line)
  25. except FileNotFoundError:
  26. print(f"Error: Input file not found at {input_filepath}")
  27. except Exception as e:
  28. print(f"An error occurred: {e}")
  32. def clean_data(line):
  33. """
  34. Removes leading/trailing whitespace from a line.
  35. """
  36. return line.strip()
  39. def convert_to_uppercase(line):
  40. """
  41. Converts a line to uppercase.
  42. """
  43. return line.upper()
  45. def replace_pattern(line, pattern, replacement):
  46. """
  47. Replaces all occurrences of a pattern in a line with a replacement string.
  48. """
  49. return re.sub(pattern, replacement, line)
  51. def extract_field(line, field_regex):
  52. """
  53. Extracts a specific field from a line using a regular expression.
  54. Returns the extracted field or None if not found.
  55. """
  56. match = re.search(field_regex, line)
  57. if match:
  58. return match.group(1) # Return the captured group
  59. else:
  60. return None
  62. def split_and_combine(line, delimiter, combine_char):
  63. """
  64. Splits a line based on a delimiter and combines the resulting parts with a character.
  65. """
  66. parts = line.split(delimiter)
  67. return combine_char.join(parts)
  70. if __name__ == '__main__':
  71. # Example Usage:
  72. # 1. Clean data and save to a new file
  73. transform_file("input.txt", "output_cleaned.txt", clean_data)
  75. # 2. Convert to uppercase
  76. transform_file("input.txt", "output_uppercase.txt", convert_to_uppercase)
  78. # 3. Replace a pattern
  79. transform_file("input.txt", "output_replaced.txt", lambda line: replace_pattern(line, r"old_pattern", "new_string"))
  81. # 4. Extract a field using regex
  82. transform_file("input.txt", "output_extracted.txt", lambda line: extract_field(line, r"(\d+)\s+name"))
  84. # 5. Split and combine
  85. transform_file("input.txt", "output_combined.txt", lambda line: split_and_combine(line, ",", "-"))

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