如何有条件地选择然后更改DataFrame的列？

Question

我正在寻找R的dplyr中的mutate_if()。例如，如何选择Int64列并将其转换为Float？

using DataFrames
df = DataFrame(A = [72, 38, 54],
               B = [1, 2, 3],
               C = ["red", "blue", "green"])
# convert integer columns to decimal columns without selecting them by name
df

Answer 1

是的。该代码将具有任何整数类型（例如Int64，Int32）的列转换为Float64。

for col in findall(x -> x <:Integer, eltypes(df))
   df[!, col] = Float64.(df2[!, col])
end