我为了见你，坐了一个小时火车 It took me one hour by train to see you. Here, it means "in purpose of" 我为你买了一束花 I bought flowers for you . Same meaning , but use in different situations

为了：in order to,with the purpose or intention of doing or achieving sth. 我为了学好汉语，需要一个语言伙伴。 为:it sometimes equal to 为了(in order to)，but it also with the Chinese meaning :给 我为你（sb.）写了一封信.