Question

由于记录是不可变的，我无法读取数据并解析它而不会创建自己的新实例。此外，我如何能够从多个特定列读取我的Excel文件，而不是从第0列读取到EOF。无论如何，我可以从第1列第3列第5列读取数据。据说，第1列将被解析为字符串，第3列将被解析为整数，第5列将被解析为长。

(defrecord Record [Name Age Index])

(defn read-csv [fname count]
  (with-open [file (io/reader fname)]
    (doall (take count (map (comp first csv/read-csv)
                            (line-seq file))))))
(def records (map #(apply ->Record %) (read-csv "C:/Users/user/Documents/URECA/hi/lib/test.csv" 1)))

这就是我所拥有的，但它似乎以递增方式读取列

Answer 1

要保留文本字段的引号，可以通过regexp解析csv文件：

(defn read-csv [fname count]
  (with-open [file (io/reader fname)]
    (doall (map #(str/split % #",") ; doesn't work with commas in text fields
                (take count (line-seq file))))))

(defn make-record [idxs types row]
  (apply ->Record
         (map (fn [idx t]
                (let [value (nth row idx)]
                  (case t
                    :string value
                    :int (Integer/parseInt value)
                    :long (Long/parseLong value))))
              idxs types)))

(def records (map (partial make-record
                           [0 2 4]
                           [:string :int :long])
                  (read-csv "/home/mobyte/test.csv" 3)))

(pprint records)
-> ({:Name "\"s1\"", :Age 1, :Index 111}
    {:Name "\"s2\"", :Age 2, :Index 112}
    {:Name "\"s3\"", :Age 3, :Index 113})

(type (:Age (first records)))
->java.lang.Integer

(type (:Index (first records)))
-> java.lang.Long

(type (:Name (first records)))
-> java.lang.String

从excel读取特定列并解析数据

1 个答案: