How to Compare Directory Trees in Python

from pathlib import Path

def compare_directories(path1, path2):
    dir1 = Path(path1)
    dir2 = Path(path2)

    if not dir1.is_dir() or not dir2.is_dir():
        raise ValueError("Both paths must be directories.")

    files1 = {p.relative_to(dir1) for p in dir1.rglob("*") if p.is_file()}
    files2 = {p.relative_to(dir2) for p in dir2.rglob("*") if p.is_file()}

    only_in_1 = files1 - files2
    only_in_2 = files2 - files1
    common = files1 & files2

    different = []
    for rel_path in common:
        file1 = dir1 / rel_path
        file2 = dir2 / rel_path
        if file1.read_bytes() != file2.read_bytes():
            different.append(str(rel_path))

    return {
        "only_in_first": sorted(str(p) for p in only_in_1),
        "only_in_second": sorted(str(p) for p in only_in_2),
        "different_content": sorted(different),
    }

if __name__ == "__main__":
    import tempfile
    import os

    with tempfile.TemporaryDirectory() as d1, tempfile.TemporaryDirectory() as d2:
        os.makedirs(os.path.join(d1, "sub"))
        os.makedirs(os.path.join(d2, "sub"))

        Path(d1, "same.txt").write_text("hello")
        Path(d2, "same.txt").write_text("hello")

        Path(d1, "diff.txt").write_text("version 1")
        Path(d2, "diff.txt").write_text("version 2")

        Path(d1, "only1.txt").write_text("only here")
        Path(d2, "only2.txt").write_text("only there")

        result = compare_directories(d1, d2)
        print(result)