Filter throwing undefined variable error

[olmohake]

In Livebook

Mix.install([
  {:explorer, "~> 0.8.2"}
])
df = Explorer.DataFrame.new(col1: ["a", "b", "c"], col2: [1, 2, 3])
Explorer.DataFrame.filter(df, col2 > 2)

=> error: undefined variable "col2"

cell:3fcusi3khmd5jay3:5

[josevalim]

You must require Explorer.DataFrame in a previous cell before. There is an open issue to improve the error message for this in Elixir. :) Thank you!