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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def convert_string_to_list(string_val):
 """Helper function to convert string to list. Used to convert shape attribute string to list format. """

    result_list = []

    list_string = string_val.split(',')
    for val in list_string:
        val = str(val.strip())
        val = val.replace("(", "")
        val = val.replace(")", "")
        val = val.replace("L", "")
        val = val.replace("[", "")
        val = val.replace("]", "")
        if val not in ("", "None"):
            result_list.append(int(val))

    return result_list