def sum_node_list(node_list):
    'Custom sum func to avoid creating redundant nodes in Python sum func.'
    from operator import add
    from functools import reduce
    return reduce(add, node_list)
Custom sum func to avoid creating redundant nodes in Python sum func.
def sum_node_list(node_list):
    
    from operator import add
    from functools import reduce
    return reduce(add, node_list)