__init__.py 文件源码

def sections(src_dim, tgt_dim):
    """Generate all boundary sections from a source dimension to a target
    dimension. For example, `sections(3,1)` generates all edges on a volume.

    The return values are lists of length `src_dim` with each element either 0,
    --1 or `None`, which are suitable for passing to
    :func:`splipy.SplineObject.section`.
    """
    # Enumerate all combinations of fixed directions
    nfixed = src_dim - tgt_dim
    for fixed in combinations(range(src_dim), r=nfixed):
        # Enumerate all {0,-1}^n over the fixed directions
        for indices in product([0, -1], repeat=nfixed):
            args = [None] * src_dim
            for f, i in zip(fixed, indices[::-1]):
                args[f] = i
            yield args