Is there any easy way to keep the headers as the keys of each row of output, if the columns are not known in advance?

[x-ji]

In the CSV library, one can simply specify headers: true to get a result like

iex> ["a;b","c;d", "e;f"]
iex> |> Stream.map(&(&1))
iex> |> CSV.decode!(separator: ?;, headers: true)
iex> |> Enum.take(2)
[
  %{"a" => "c", "b" => "d"},
  %{"a" => "e", "b" => "f"}
]

However, I haven't been able to figure out a way to easily do it with nimble_csv.

There is an example of

"name\tage\njohn\t27"
|> MyParser.parse_string
|> Enum.map(fn [name, age] ->
  %{name: name, age: String.to_integer(age)}
end)

However, this requires me to know in advance:

1. How many columns the file will have
2. The name of each column

My use case is to handle CSV files with potentially unknown columns. But I need to produce a map as in the first example.

Seems that the only way to do it with nimble_csv would be to

1. specify headers: false
2. take the head of the resulting list as the keys
3. Perform a Enum.map on the tail of the list to add the keys one by one.

Which seems to be quite convoluted. Did I not understand the library correctly and there's an easy way to do it? Or is my use case not suited to nimble_csv here/I should rethink my approach?

[josevalim]

Today you can only skip the headers (if you know them upfront) OR do this:

[headers | rest] = MyParser.parse_string "name\tage\njohn\t27"
Enum.map(rest, fn row -> Enum.zip(headers, row) end)

It is not convoluted per se but something do you have to do yourself.

[x-ji]

Thanks for the quick reply and help. This makes sense.