def word_search(documents, keyword):
    """
    Takes a list of documents (each document is a string) and a keyword. 
    Returns list of the index values into the original list for all documents 
    containing the keyword.

    Example:
    doc_list = ["The Learn Python Challenge Casino.", "They bought a car", "Casinoville"]
    >>> word_search(doc_list, 'casino')
    >>> [0]
    """
    
    indices = []
    for i, doc in enumerate(documents):
        tokens = doc.split()
        normalized = [token.rstrip('.,').lower() for token in tokens]
        if keyword.lower() in normalized:
            indices.append(i)
    return indices

