Missing something when going through the Little Elixir book. Made my own function to grab a csv and make weather requests.

The result is the result of the first operation (a correct temperature response from a service, followed by the cities list. I expected a list of outputs only. Any pointers?

def get_cities_weather(csv_path) do
  alias NimbleCSV.RFC4180, as: CSV

  cities = csv_path
  |> File.stream!
  |> CSV.parse_stream
  |> Stream.map(fn [city, city_ascii, lat, lng, pop, country, iso2, iso3, province] ->
      %{name: city_ascii, lat: lat, lng: lng}
    end)

  cities
  |> Enum.map_every(500, fn city ->
    Metex.Worker.temperature_of(city)
  end)

end

Produces:

[{:ok, 40.8}, %{lat: "34.5167011", lng: "65.25000063", name: "Chaghcharan"},
 %{lat: "31.58299802", lng: "64.35999955", name: "Lashkar Gah"},
 %{lat: "31.11200108", lng: "61.88699752", name: "Zaranj"},
 %{lat: "32.63329815", lng: "65.86669865", name: "Tarin Kowt"},
 %{lat: "32.85000016", lng: "68.41670453", name: "Zareh Sharan"}...]