how to compare 3 columns in excel code example

Example 1: select columns to include in new dataframe in python

new = old[['A', 'C', 'D']].copy()

Example 2: reorder columns in r

col_order <- c("Species", "Petal.Width", "Sepal.Length",
               "Sepal.Width", "Petal.Length")
my_data2 <- my_data[, col_order]
my_data2

# or
my_data2 <- my_data[, c(5, 4, 1, 2, 3)]