python笔记：readline和readlines

log日志格式如下，自己拼吧
2016-10-21 21:08:00,039 [7 KinectServer]INFO: 14
2016-10-21 21:08:00,045 [7 KinectServer]INFO: 103
2016-10-21 21:08:00,053 [7 MainWindowForm]INFO: 118.1132

# 主要是讲readline()和readlines()的区别，readlines读取到的是所有行组成的列表，readline读取的是文件中的一行
def count_avg_time2():
    try:
        list_last_column = []
        total = 0
        avg = 0
        with open("jcl.log", "r", encoding="utf-8") as f:
            for line in f.readlines():
                line = [i for i in line.split()]
                if not line:
                    break
                list_last_column.append(float(line[-1]))
        # return list_last_column
        if list_last_column:
            for i in list_last_column:
                total = total + i
            avg = total / len(list_last_column)
        return avg

    except Exception as e:
        print(e)


def count_avg_time3():
    try:
        list_last_column = []
        total = 0
        avg = 0
        with open("jcl.log", "r", encoding="utf-8") as f:
            while True:
                # 这是readline()
                lines = f.readline()
                # print(f.readlines())
                # print(type(lines))
                if not lines:
                    break
                item = [i for i in lines.split()]
                list_last_column.append(float(item[-1]))

        if list_last_column:
            for i in list_last_column:
                total = total + i
            avg = total / len(list_last_column)
        return avg

    except Exception as e:
        print(e)


if __name__ == "__main__":

    # avg_time2 = count_avg_time2()
    # print(avg_time2)

    avg_time3 = count_avg_time3()
    print(avg_time3)