Randomly remove records from a CSV file

remove_records_from_csv.py

# the majority of the script was created by ChatGPT responding to the prompt "is there a python function that can randomly remove records from a CSV file?"

import csv
import random
import sys

def remove_records(input_file, output_file, remove_fraction=0.1):
    """
    Randomly removes a fraction of records from a CSV file.
    
    :param input_file: Path to the input CSV file
    :param output_file: Path to the output CSV file after removal
    :param remove_fraction: Fraction of records to remove (default is 10%)
    """
    try:
        with open(input_file, 'r', newline='', encoding='utf-8') as infile:
            reader = list(csv.reader(infile))
            
            if len(reader) <= 1:
                print("Not enough records to process.")
                return

            header, rows = reader[0], reader[1:]  # Separate header from data
            num_to_remove = int(len(rows) * remove_fraction)
            
            rows_to_keep = random.sample(rows, len(rows) - num_to_remove)  # Random selection of remaining rows

        with open(output_file, 'w', newline='', encoding='utf-8') as outfile:
            writer = csv.writer(outfile)
            writer.writerow(header)  # Write header back
            writer.writerows(rows_to_keep)  # Write remaining rows

        print(f"Removed {num_to_remove} records. Output saved to {output_file}")
    except (Exception, EnvironmentError) as e:
        tbE = sys.exc_info()[2]
        # Write the line number the error occured to the log file
        # update to use code to get name of file
        print(f'error at Line {tbE.tb_lineno}')
        # Write the error print( to the log file
        print(f'error: {e}')