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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 lead(expr, offset, default=None, sort=None, ascending=True):
 """ Get value in the row ``offset`` rows after to the current row. :param offset: the offset value :param default: default value for the function, when there are no rows satisfying the offset :param expr: expression for calculation :param sort: name of the sort column :param ascending: whether to sort in ascending order :return: calculated column """

    return _shift_op(expr, Lead, offset, default=default,
                     sort=sort, ascending=ascending)