有了新的输入更新版本，下面是另一个解决方案

A = LOAD '/user/data/split.txt' as line:chararray;
B1 = filter A by $0  matches '1.*';
B2 = filter A by $0  matches '2.*';
or 
SPLIT A INTO B1 IF ($0  matches '1.*'), B2 IF ($0  matches '2.*');

这里有一个方法。。。

A = LOAD '/user/data/split.txt' as line:chararray;
B  = FOREACH A GENERATE  Flatten(TOKENIZE(line,' ')) ;
B1 = filter B by $0  matches '1.*';
B2 = filter B by $0  matches '2.*';
DUMP B1
DUMP B2
 or 
 SPLIT B INTO B1 IF ($0  matches '1.*'), B2 IF ($0  matches '2.*');