Function to sample without replacement and optionally include or exclude items

sample.py

def sample(seq: Sequence, k: int, include: Union[None, set] = None, exclude: Union[None, set] = None) -> Sequence:
    """Samples `k` items from `seq` without replacement, optionally including or excluding items."""

    # pre-condition
    assert k >= 0, "Number of items to sample must be non-negative"
    assert k <= len(seq), f"Cannot sample {k} items without replacement from a sequence with {len(seq)} items"

    if include is None:
        include = set()
    
    if exclude is None:
        exclude = set()
    
    filtered_exclude = set(item for item in exclude if item in seq)
    
    assert len(include) <= k, "Number of items to include can't exceed number of items to sample"
    assert len(seq) - len(filtered_exclude) >= k, "Not enough items to sample from sequence after excluding items"
    assert len(include.intersection(exclude)) == 0, "Sets `include` and `exclude` must be mutually exclusive"
    
    # sample
    filtered_seq = [item for item in seq if item not in include.union(exclude)]
    sampled = random.sample(filtered_seq, k-len(include)) + list(include)
    sampled = random.sample(sampled, k)
    
    # post-condition
    assert len(sampled) == k, "Sampled items must be of length `k`"
    
    for item in include:
        assert item in sampled, "Sampled items must include all items in `include`"
    
    for item in exclude:
        assert item not in sampled, "Sampled items must not include any items in `exclude`"
    
    return sampled


sample(["dog", "cat", "lizard"], k=2, include={"dog"}, exclude={"lizard"})  # ["dog", "cat"]