Rounding all columns excep first one - power query - rounding

Question

I have question - is that possible to use for rounding all columns except first one?
I use some clue from changing data types from Alexis Olson (thank you it is veeeery usefull), but I cannot add to this syntax rounding.
When using syntax
= Table.TransformColumns(
#"Rename column",
List.Transform(
List.RemoveFirstN(Table.ColumnNames(#"Rename"),1),
each Number.Round(_, 0))
)
appears - Expression.Error: Value "2019_1" cannot be transferred to type Number - for explain 2019_1 is header value.
Can anybody help me, please?
Thank you very much in advance
Jiri

Answer 1

Use this code:
round = Table.TransformColumns(Source,List.Transform(List.Skip(Table.ColumnNames(Source)),
each {_, Number.Round}))
Number.Round here is equivalent to Number.Round(_,0).
P.S. I usually use 3rd argument of Number.Round (rounding mode), for instance, if you wish to round 0.5 to 1: Number.Round(_, 0, 2)

Answer 2

You should return a list of lists, where first element is a column name and second - a function that is applied to value. But not list of functions only
let
Source = #table({"first", "second", "third", "fourth"},{
{ 1, 2, 3, 4},
{1.1, 2.2, 3.7, 4.9}
}),
cols = Table.ColumnNames(Source),
cols_1 = List.RemoveFirstN(cols, 1),
transformation_list = List.Transform(cols_1, (column_name)=>{column_name, (value)=>Number.Round(value, 0)}),
round = Table.TransformColumns(Source, transformation_list)
in
round
So transformation_list is