Calculates the hash code of given columns, and returns the result as an int column.

    >>> spark.createDataFrame([('ABC',)], ['a']).select(hash('a').alias('hash')).collect()
    [Row(hash=-757602832)]

def hash(*cols):
    """Calculates the hash code of given columns, and returns the result as an int column.

    >>> spark.createDataFrame([('ABC',)], ['a']).select(hash('a').alias('hash')).collect()
    [Row(hash=-757602832)]
    """
    sc = SparkContext._active_spark_context
    jc = sc._jvm.functions.hash(_to_seq(sc, cols, _to_java_column))
    return Column(jc)