human
Solve the following python programming problem given the following code:
def generate_html(output_filename, tree, my_index, info, path, footer = '') : 
    'Generate HTML for a tree node.

    ``output_filename`` is the output file name.

    ``tree`` is the root node of the tree.

    ``my_index`` is the path of the node for which you are generating this HTML
    file.

    ``info`` is a list of paths of child nodes.

    ``path`` is the directory name for the plain-text report files.
    ' 
    html = open (footer, 'w') 
    print ((HEADER % { 
        'name' : index_to_name (my_index), 
}), file = html) 
    info = [(tree.get_at (node_path), node_path) for node_path in info] 
    def key(node_info) : 
        (node, node_path) = node_info 
        return (len (node_path), (- node.uncovered), (node_path and node_path [(- 1)])) 
info.sort (key = key) 
    for (node, file_index) in info : 
        if (not file_index) : 
            continue 
print_table_row (html, node, file_index) 
print ('</table><hr/>', file = html) 
    print (tree.get_at (my_index).html_source, file = html) 
    print ((FOOTER % footer), file = html) 
    html.close () 

    
    

    Fix the buggy line: html = open (footer, 'w')
assistant
#Here is Python program to fix the buggy line: html = open (footer, 'w')
.

html = open (output_filename, 'w')