Is there a way to read a DataFrame from file specifying the type of each column?

New to Julia
7

Why exactly do you want a CSV.File? If you want to end up with a DataFrame you can use DataFrame as sink in CSV.read.

You could just manually convert after reading, using something like

julia> df = CSV.read("test.csv", DataFrame)  # initial DataFrame
2×3 DataFrame
 Row │ Col1   Col2     Col3
     │ Int64  Float64  String3
─────┼─────────────────────────
   1 │     1    2.3    sdf
   2 │    12   -0.213  ds

julia> for (col_symb, col_type) in zip((:Col1, :Col3), (Float32, String))
           df[!, col_symb] .= convert.(col_type, df[!, col_symb])
       end

julia> df
2×3 DataFrame
 Row │ Col1     Col2     Col3
     │ Float32  Float64  String
─────┼──────────────────────────
   1 │     1.0    2.3    sdf
   2 │    12.0   -0.213  ds

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