问题
The below pig script gives the count of various characters in a file. It works for all characters except ','.
My code :
A = load 'a.txt';
B = foreach A generate flatten(TOKENIZE((chararray)$0)) as word;
C = filter B by word matches '(.+)';
D = foreach C generate flatten(TOKENIZE(REPLACE(word,'','|'), '|')) as letter;
E = group D by letter;
F = foreach E generate COUNT(D), group;
store F into 'pigfiles/wordcount';
This matches all characters except ',' and gives an output.
Input: (cat a.txt)
HI, I.
Output:(output in file generated)
1 H
2 I
1 .
It doesn't give the count of , in the file. I don't understand why it isn't giving the count of ',' !
回答1:
The first tokenize will eliminate the token separators space, double quote("), coma(,) parenthesis(()), star(*).Instead use replace to tokenize each character and then count.See below
Input
HI, I.
PigScript
A = LOAD 'test3.txt';
B = FOREACH A GENERATE FLATTEN(TOKENIZE(REPLACE((chararray)$0,'','|'), '|')) AS letter;
C = FILTER B BY letter != ' ';
D = GROUP C BY letter;
E = FOREACH D GENERATE COUNT(C.letter), group;
DUMP E;
Output
来源：https://stackoverflow.com/questions/36930492/how-to-match-in-pig