# How to deal with a Nullable DataFrame?

**URL:** <https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013>\
**Category:** General Usage\
**Created:** [June 6, 2019, 4:01pm UTC](https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013 "2019-06-06T16:01:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jayce\_ram](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jayce_ram/32/3977_2.png) [@jayce\_ram](https://discourse.julialang.org/u/jayce_ram)\
**Post date:** [June 6, 2019, 4:01pm UTC](https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013/1 "2019-06-06T16:01:57Z")

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I have a pretty huge csv file that contains missing values. In this case, the data of my dataframe becomes Nullable types. I have tried to apply the operation :

```julia
df = unique!(df[:city]) 

```

```julia
LoadError: e[91mMethodError: no method matching unique!(::NullableArrays.NullableArray{WeakRefString{UInt8},1})e[0m

```

and i got a message error. I also have tried to apply the function get.(df) but it seems not work neither.  
How can I even make this operation and others one with a nullable dataframe ?  
I have been using JunoPro 0.6.2.2 and I cannot update to new julia version yet.  
Thanks for your help.

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**Author:** ![nalimilan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nalimilan/32/147_2.png) [@nalimilan](https://discourse.julialang.org/u/nalimilan)\
**Post date:** [June 6, 2019, 9:16pm UTC](https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013/2 "2019-06-06T21:16:39Z")

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`NullableArray` has been deprecated for a long time. You should really migrate to `missing`, which exists even on Julia 0.6 (but it is slow) via the Missings.jl package.

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**Author:** ![jayce\_ram](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jayce_ram/32/3977_2.png) [@jayce\_ram](https://discourse.julialang.org/u/jayce_ram)\
**Post date:** [June 7, 2019, 7:36am UTC](https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013/3 "2019-06-07T07:36:04Z")

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Thanks for your answer! I just cannot see how to combine Missings.jl package with the action of reading my csv file .  
Julia convert my dataframe in Nullable just because I have missing values. I have not decided to use Nullable, that’s Julia that automatically do that.  
I have not found the way to use Missing at the moment of reading my csv file.  
Could you help me with that ?  
Thanks !

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<div class="post-metadata">

**Author:** ![nalimilan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nalimilan/32/147_2.png) [@nalimilan](https://discourse.julialang.org/u/nalimilan)\
**Post date:** [June 7, 2019, 9:43am UTC](https://discourse.julialang.org/t/how-to-deal-with-a-nullable-dataframe/25013/4 "2019-06-07T09:43:23Z")

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Sorry, but I don’t remember how things worked exactly on Julia 0.6. You’d really better upgrade to 0.7.