Process a confusion matrix in Haskell

confmat.hs

import Data.Char (isSpace)
import Data.List.Split (splitOn)

-- Trim the right side of the string from extraneous whitespace (\r)
trim :: String -> String
trim str | all isSpace str = ""
trim (c:cs) = c : trim cs

-- Process a single row of the matrix.
rowToString :: String -> [String] -> [Int] -> [String]
rowToString _ [] _ = []
rowToString _ _ [] = []
rowToString prefix (h:hs) (x:xs) = stringList ++ rowToString prefix hs xs
    where stringList = take x $ repeat replacementString
          replacementString = prefix ++ "\t" ++ h

-- Recursively process all rows
processMatrix :: ([String], [[String]]) -> [String]
processMatrix (h, []) = []
processMatrix (h, (r:rs)) = rowResult ++ processMatrix (h, rs)
    where rowResult = rowToString (head r) h (map read $ tail r)

-- Read the matrix in a usable format
readMatrix :: String -> ([String],[[String]])
readMatrix = (\x -> (tail $ head x, tail x)) . map (splitOn "\t") . map trim . lines

main = mapM_ putStrLn . processMatrix . readMatrix =<< readFile "data.txt"

confmat.py

def generateString(header, row):
    original, counts = row[0], row[1:]
    string = ""
    for i, count in enumerate(counts):
        new_string = (original + "\t" + header[i] + "\n") * int(count)
        string += new_string
    if string != "":
        return string.strip('\n')
    else:
        return None

if __name__ == "__main__":
    with open("data.txt") as f:
        content = f.readlines()
    content = [line.strip('\r\n').split('\t') for line in content]
    header, body = content[0][1:], content[1:]
    for row in body:
        result = generateString(header, row)
        if result is not None:
            print result

data.txt

	.	b	mb	w
.	0	0	0	0
b	2	11	3	0
mb	0	0	0	0
w	0	0	0	2

result.txt

b	.
b	.
b	b
b	b
b	b
b	b
b	b
b	b
b	b
b	b
b	b
b	b
b	b
b	mb
b	mb
b	mb
w	w
w	w