<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def format_string(format, *cols):
 """ Formats the arguments in printf-style and returns the result as a string column. :param col: the column name of the numeric value to be formatted :param d: the N decimal places [Row(v=u'5 hello')] """

    sc = SparkContext._active_spark_context
    return Column(sc._jvm.functions.format_string(format, _to_seq(sc, cols, _to_java_column)))