import sys import re def solve(lines): return [l for l in lines if re.search(r"\bpies\b", l, re.I)] if __name__ == "__main__": lines = [] fp = sys.argv[1] print(fp) with open(fp, encoding="utf-8") as f: lines = f.readlines() sol = solve(lines) with open("./polish_wiki_excerpt.out", 'w', encoding="utf-8") as f: f.writelines(sol)