def clean_schema(lst):
    """This method cleans the list items so that they can be compared.
       - Strips space
       - Remove trailing/leading spaces
       - convert to lower case

    Args:
        lst (list): List to be cleaned
    
    Returns:
    list : Cleaned list
    """
    schema=[]
    for col in lst:
        col=col.lower().strip()
        col=" ".join(col.split())
        schema.append(col)
    
    return schema