files.py 文件源码

def dehead_filetree(tree: ExtractFileTree) -> ExtractFileTree:
    """Remove the head of the given filetree while preserving the old head
    name.

    So a tree ``{1: [2: [3: [4: [f1, f2]]]}`` will be converted to
    ``{1: [f1, f2]}``.

    :param dict tree: The file tree as generated by :py:func:`extract`.
    :returns: The same tree but deheaded as described.
    :rtype: dict
    """
    assert len(tree) == 1
    head_node = list(tree.keys())[0]
    head = tree[head_node]

    while (
        isinstance(head, t.MutableSequence) and len(head) == 1 and
        isinstance(head[0], t.MutableMapping) and len(head[0]) == 1
    ):
        head = list(head[0].values())[0]

    tree[head_node] = head

    return tree