How to check for 'not in' in if statements?

[jnthnclrk]

@Jura

{{ if isset .Params “categories” }} {{ if not (in .Params.categories “Meta”) }} <!-- Hugo code here –> {{ end }} {{ end }}

I can’t get this working. Here is what I have:

{{ range .Site.Pages}}
    {{ if not (in .Params.categories "Nutrition") }}
        <!-- HTML goes here -->
    {{ end }}
{{ end }}

And here is the Hugo error:

ERROR 2018/09/20 10:30:00 Error while rendering “home” in “”: template: index.html:61:7: executing “index.html” at <partial “aside.html”…>: error calling partial: template: partials/aside.html:14:62: executing “partials/aside.html” at <delimit .Params.cate…>: error calling delimit: can’t iterate over

Can anyone spot what I’m doing wrong?