python - 如何在 Python 3 中合并两个 tar gz BinaryIO

Question

我有两个二进制 I/O 流（都继承BufferedIOBase），它们代表两个用 gzip 算法压缩的 tar 档案。

是否有任何有效的方法来创建第三个，即其他两个的组合？

我尝试通过将两个流转换为tarfile.Tarfile通过fileobj参数并将每个成员添加到第三个成员：

def merge_environment(a: Optional[BinaryIO], b: Optional[BinaryIO]) -> Optional[BinaryIO]:
    """Merge <a> and <b>, returning a new tarfile.TarFile object.

    If two files in <a> and <b> have the same name, the one in <a> prevails."""
    destio = io.BytesIO()

    with tarfile.open(fileobj=a, mode="r:gz") as t1, \
            tarfile.open(fileobj=b, mode="r:gz") as t2, \
            tarfile.open(fileobj=destio, mode="w:gz") as dest:

        t1_members = [m for m in t1.getmembers() if m.name != ""]
        t1_names = [m.name for m in t1.members]
        t2_members = [m for m in t1.getmembers() if m.name != "" and m.name not in t1_names]

        for member in t1_members:
            dest.addfile(member, t1.extractfile(member))
        for member in t2_members:
            dest.addfile(member, t2.extractfile(member))

    destio.seek(0, 0)
    return destio

但是，如果任何tar.gz包含目录，tarfile.extractfile()则这不起作用，因为在目录上不起作用。

有什么解决办法吗？

标签： pythonpython-3.xtarfile

Answer 1

解决方案很简单，fileobj参数 oftarfile.addfile不是强制性的，tarinfo就足够了：

destio = io.bytesIO()
with tarfile.open(fileobj=a, mode="r:gz") as t1, \
        tarfile.open(fileobj=b, mode="r:gz") as t2, \
        tarfile.open(fileobj=destio, mode="w:gz") as dest:

    t1_members = [m for m in t1.getmembers()]
    t1_names = t1.getnames()
    t2_members = [m for m in t2.getmembers() if m.name not in t1_names]

    for member in t1_members:
        if member.isdir():
            dest.addfile(member)
        else:
            dest.addfile(member, t1.extractfile(member))

    for member in t2_members:
        if member.isdir():
            dest.addfile(member)
        else:
            dest.addfile(member, t2.extractfile(member))