Uniquify

import os
from collections import Counter

dir_path = os.getcwd()

files = [f for f in os.listdir(dir_path) if f.endswith('.txt')]
unique_lines = set()
for file in files:
    with open(os.path.join(dir_path, file), 'r') as f:
        lines = [line.strip() for line in f.readlines()]
    unique_lines.update(lines)
line_counts = Counter()
for file in files:
    with open(os.path.join(dir_path, file), 'r') as f:
        lines = [line.strip() for line in f.readlines()]
        line_counts.update(lines)
common_lines = [line for line, count in line_counts.items() if count == len(files)]
for file in files:
    new_filename = os.path.join(os.path.dirname(file), "c_" + os.path.basename(file))
    with open(os.path.join(dir_path, file), 'r') as f:
        with open(new_filename,'w', encoding='utf-8') as new_file:
            lines = [line.strip() for line in f.readlines()]
            new_lines = [line for line in lines if line not in common_lines]
            new_file.write('\n'.join(new_lines))
print("Success.")