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stringf#containsdeedle

F# Deedle Filtering a data frame using String.Contains

I have a data frame that looks like this

          Date                        Type   last  LastSize       
12    -> 2013-10-25T00:00:00.575556Z  trade 273  20     
13    -> 2013-10-25T00:00:00.575556Z  quote 0    0       
:         ...                         ...    ...   ...      
26554 -> 2013-10-25T06:04:59.741493Z  trade 273  2       
26555 -> 2013-10-25T06:04:59.751844Z  trade 273  8

I want to filter based on the field labelled Type. Specifically I want to filter the data frame to only includes rows where the column Type contains the string "trade". 

let tradesOnly = lastFrame.GetSeries<string>("Type")
                |> Series.filterValues (fun t -> t.Contains "trade")

This will correctly filter but only gives me the series as I am using GetSeries. The Deedle samples include have a snippet somewhat like this

let x = lastFrame.RowsDense 
        |> Series.filterValues (fun row -> row.GetAs<string>("Type") = "trade")
        |> Series.countValues

This compiles but return an empty data frame as I need contains not equals. How can filter a frame by string contains? `

Solution

  • row.GetAs<string>("Type").Contains("trade") should do it.