# CSV, white spaces and data type. Force Float on empty fields

**URL:** <https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702>\
**Category:** General Usage\
**Tags:** csv\
**Created:** [January 21, 2021, 3:31am UTC](https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702 "2021-01-21T03:31:21Z")\
**Posts on this page:** 4\
**Page:** 2

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**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [January 21, 2021, 4:45pm UTC](https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702/21 "2021-01-21T16:45:57Z")

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Yes, when I removed the `missingstring=" "` option then the `tryparse` worked. With the `missingstring` on, it errors

```julia
julia> tryparse.(Float64,isc[!, :smajax])
ERROR: MethodError: no method matching tryparse(::Type{Float64}, ::Missing)
Closest candidates are:
  tryparse(::Type{Float64}, ::String) at parse.jl:247
  tryparse(::Type{Float64}, ::SubString{String}) at parse.jl:252
  tryparse(::Type{T}, ::AbstractString) where T<:Union{Float32, Float64} at parse.jl:287

```

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**Author:** ![pdeffebach](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pdeffebach/32/10320_2.png) [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Post date:** [January 21, 2021, 6:01pm UTC](https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702/22 "2021-01-21T18:01:27Z")

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Yes, it’s the explanation I gave abote. `passmissing(tryparse(Float64, missing))` returns `missing` instead of `nothing`.

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<div class="post-metadata">

**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [January 21, 2021, 6:14pm UTC](https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702/23 "2021-01-21T18:14:41Z")

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I think you mean `passmissing(tryparse)(Float64, missing)` - we’re not having a lot of luck with correctly typing this out today 😃

FWIW I downloaded your data and am getting all String columns (irrespective of any `missing` values - it seems to me that `missingstrings = [" "^i for i in 1:8]` catches them all), so not sure how you’re managing to get any Floats 🤷‍♂️

There are a few other discussions I found on here around fixed width files which suggest CSV.jl should be able to handle them with `ignorerepeated = true`, but that doesn’t help in my tests either. Maybe there should be a `trim_whitespace` kwarg like in readr’s CSV parser.

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<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [January 21, 2021, 7:48pm UTC](https://discourse.julialang.org/t/csv-white-spaces-and-data-type-force-float-on-empty-fields/53702/24 "2021-01-21T19:48:06Z")

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Sorry had to leave for a Zoom.  
I’m Windows. I don’t see why we would have different column types with the same fime and same commands. Ah, I’m also on “v1.6dev”

Edit: nope, tried with 1.5 and still get Floats and Strings

```julia
julia> isc = CSV.File("isc-gem-cat.csv", header=93, normalizenames=true, dateformat=Dates.DateFormat("yyyy-mm-dd HH:MM:SS.sss")) |> DataFrame
39160×31 DataFrame
   Row │ _date lat lon smajax sminax strike q depth unc q_1 mw unc_1 q_2 s mo fac mo ⋯
       │ DateTime Float64 Float64 String String String String Float64 Float64 String Float64 Float64 String String String String St ⋯
───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
     1 │ 1904-04-04T10:02:34.56 41.802 23.108 8.6 6.6 164.2 B 15.0 4.8 C 6.84 0.4 C d 2.30 19 b ⋯
     2 │ 1904-04-04T10:26:00.88 41.758 23.249 8.3 6.9 15.2 B 15.0 4.8 C 7.02 0.4 C d 4.20 19 b
     3 │ 1904-06-25T14:45:39.14 51.424 161.638 33.6 18.7 116.2 C 15.0 25.0 C 7.5 0.4 C d 2.60 20 b

```

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