Hi @Fire-Hound, welcome to the forum!

Few points:

1. You can filter the dtype as part of the comprehension, and you don’t need 0..73:

   for col <- across(), col.dtype == {:f, 64} do
   

2. When you say you want to make sure there are no infinities, do you want to check? Or do you want to replace (impute) them?

   If you just want to check, this will work:

   require Explorer.DataFrame, as: DF
   
   df = DF.new(a: [:infinity, 1.0, 2.0], b: [0.0, 1.0, 2.0], c: ["x", "y", "z"])
   
   DF.summarise(df,
     for col <- across(), col.dtype == {:f, 64} do
       {col.name, any?(is_infinite(col))}
     end
   )
   
   # #Explorer.DataFrame<
   #   Polars[1 x 2]
   #   a boolean [true]
   #   b boolean [false]
   # >
   

   If you want to impute, you’ll want this:

   DF.mutate(df,
     for col <- across(), col.dtype == {:f, 64} do
       {col.name, if(is_infinite(col), do: :nan, else: col)}
     end
   )
   
   # #Explorer.DataFrame<
   # Polars[3 x 3]
   #   a f64 [NaN, 1.0, 2.0]
   #   b f64 [0.0, 1.0, 2.0]
   #   c string ["x", "y", "z"]
   # >