如何在F#中编写csv?

时间:2018-06-30 03:57:09

标签: f#

我如何将F#中的记录写入csv?对于某个变量的每个实例最好有一行。我的记录和最终输出是一张下面的地图。

type Family =
    { Month : int
      Year : int
      Income : float
      Family : int
      Dogs : int
      Cats : int
    }

let monthly =
    timeMap
    |> Seq.ofList
    |> Seq.map(fun ((month,year), rows) ->
        { Month = month
          Year = year
          Income = rows.Inc
          Family = familyMap.[(month,year)].Children
          Dogs = familyMap.[(month,year)].Dogs
          Cats = familyMap.[(month,year)].Cats
        })
    |> List.ofSeq

let map = 
    monthly
    |> List.map (fun x -> (x.Year,x.Month),x)
    |> Map.ofList 

已编辑

这是我尝试过的方法,但是遇到了(A,B,C,D,E,F) are not definedit is recommended that I use the syntax new (type) args的错误。最后一个错误显示在>> MyCsvType

type MyCsvType = CsvProvider<Schema = "A (int), B (int), C (float), D (int), E (int), F (int)", HasHeaders = false>
let myCsvBuildRow (x:Family) = MyCsvType.Row(x.A,x.B,x.C,x.D,x.E,x.F)
let myCsvBuildTable = (Seq.map myCsvBuildRow) >> Seq.toList >> MyCsvType
let myCsv = monthly|> myCsvBuildTable
myCsv.SaveToString()

1 个答案:

答案 0 :(得分:5)

您的代码几乎可用,除了myCsvBuildRow函数需要使用其正确名称访问Family类型的成员。在您的版本中,您正在访问诸如AB等名称,但是这些是CSV文件中列的名称,而不是F#记录的成员的名称。以下对我有用:

type MyCsvType = CsvProvider<Schema = "A (int), B (int), C (float), D (int), E (int), F (int)", HasHeaders = false>

let myCsvBuildRow (x:Family) = 
  MyCsvType.Row(x.Month,x.Year,x.Income,x.Family,x.Dogs,x.Cats)
let myCsvBuildTable data = 
  new MyCsvType(Seq.map myCsvBuildRow data)

let myCsv = family |> myCsvBuildTable
myCsv.SaveToString()