给我一段python代码，提取ratio_avg,0.3040706318225739,1 perclos,0.1,1 ratio_avg,0.29619502717213075,2 perclos,0.1,2 ratio_avg,0.2977856306116322,3 perclos,0.1,3 ratio_avg,0.298256166378347,4 perclos,0.1,4 ratio_avg,0.298589205467087,5 perclos,0.1,5 ratio_avg,0.3005083686230243,6 perclos,0.1,6 ratio_avg,0.2981722974161423,7 perclos,0.1,7 ratio_avg,0.30025224530468264,8 perclos,0.1,8 ratio_avg,0.30056005238736205,9 perclos,0.1,9 ratio_avg,0.29734692150973696,12里面ratio_avg行

好的，以下是一段可以提取上述字符串中`ratio_avg`行的Python代码：

data = "ratio_avg,0.3040706318225739,1 perclos,0.1,1 ratio_avg,0.29619502717213075,2 perclos,0.1,2 ratio_avg,0.2977856306116322,3 perclos,0.1,3 ratio_avg,0.298256166378347,4 perclos,0.1,4 ratio_avg,0.298589205467087,5 perclos,0.1,5 ratio_avg,0.3005083686230243,6 perclos,0.1,6 ratio_avg,0.2981722974161423,7 perclos,0.1,7 ratio_avg,0.30025224530468264,8 perclos,0.1,8 ratio_avg,0.30056005238736205,9 perclos,0.1,9 ratio_avg,0.29734692150973696,12"
ratio_lines = [line for line in data.split() if line.startswith('ratio_avg')]
print(ratio_lines)

这段代码将待处理的字符串赋值给`data`变量，并使用`split()`方法将其转换为列表，列表中的每个元素是原字符串中以空格分隔的部分。然后，使用列表推导式筛选出以`ratio_avg`开头的行，并将其保存在`ratio_lines`列表中。最后，使用`print()`函数输出`ratio_lines`列表的内容。