# How to groupby a column and take the mean while ignoring missing values

**URL:** https://discourse.julialang.org/t/how-to-groupby-a-column-and-take-the-mean-while-ignoring-missing-values/37918
**Category:** General Usage
**Created:** [April 20, 2020, 7:44pm UTC](https://discourse.julialang.org/t/how-to-groupby-a-column-and-take-the-mean-while-ignoring-missing-values/37918 "2020-04-20T19:44:14Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![Julia1](https://avatars.discourse-cdn.com/v4/letter/j/db5fbb/32.png) [@Julia1](https://discourse.julialang.org/u/Julia1)
#### Post date: [April 20, 2020, 7:44pm UTC](https://discourse.julialang.org/t/how-to-groupby-a-column-and-take-the-mean-while-ignoring-missing-values/37918/1 "2020-04-20T19:44:14Z")

</div>

Hi how’s it going,

I’m trying to do by(df, col1, numeric\_col=\>mean)

however it’s not working. I tried skipmissing=true but turns out that skips any group that has even 1 missing value. If the values of numeric\_col for a group are [1,3,missing,missing] I would like it to return 2 and essentially ignore rows that are missing.

Thanks

---

<div class="post-metadata">

### Author: ![Mattriks](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mattriks/32/351_2.png) [@Mattriks](https://discourse.julialang.org/u/Mattriks)
#### Post date: [April 20, 2020, 8:36pm UTC](https://discourse.julialang.org/t/how-to-groupby-a-column-and-take-the-mean-while-ignoring-missing-values/37918/2 "2020-04-20T20:36:06Z")

</div>

```julia
by(df, :g, :x=>mean∘skipmissing)

?∘

```