import csv

with open("school_subject_grade_summary.csv", "r", encoding="utf-8", newline="") as f:
    reader = csv.DictReader(f)
    for i, row in enumerate(reader, start=1):
        code = row["school_code"]
        if "\r" in code or "\n" in code:
            print(f"Row {i}: DIRTY school_code -> {repr(code)}")