marcin

marcin

Hi!

I’d like to parse a CSV rows into typed elements, without knowing what is the schema (column order) of the CSV.

In ruby the CSV library will parse strings into types. In Elixir, both csv and nimble_csv libraries produce string values, and the caller is responsible for casting them into other types (integer, decimal, date-times).

For integer and decimal columns, I can detect if they contain just numbers and decimal point – with regexp or maybe binary matching?
For dates I have no idea how to proceed. I’m aware that date time format is not specified by rfc4180 – files I am parsing have dates in format: “2016-12-01 10:36:29.772554”.

What would you recommend? I am surprised this seemingly simple problem doesn’t have an obvious solution!

m.

Showing Posts 1 to 5

LostKobrakai

LostKobrakai

Probably because it’s only “seemingly simple”. I can remember cursing at PHP’s strtotime a few times, because parsing dates without knowing the format is hardly more then guesswork and hoping for the best. If you know the format though you should be able to use timex to parse it.

dimitarvp

dimitarvp

iex> Timex.parse!("2016-12-01 10:36:29.772554", "%Y-%m-%d %H:%M:%S.%f", :strftime)
~N[2016-12-01 10:36:29.772554]

Not sure if you are receiving datetimes formatted in other ways but this should sort you up as a start.

peerreynders

peerreynders

Am I missing something?

iex(1)> NaiveDateTime.from_iso8601("2016-12-01 10:36:29.772554")
{:ok, ~N[2016-12-01 10:36:29.772554]}

That date can then be “enhanced” with DateTime.from_naive/3.

dimitarvp

dimitarvp

Nope, you aren’t missing anything. I simply prefer being explicit – plus I can never remember what passes for which standard.

peerreynders

peerreynders

I guess if you already need Timex for something else.

I’d be willing to massage the string a bit to be able to use the standard functionality and ditch a dependency - and ISO8601 has pretty good coverage (am/pm could be a bit awkward).

— All posts loaded —

Where Next? Top

Trending in Questions Top

RSP87
I’m working on a project that simulates the bumbl example in the programming phoenix book. It acts almost like an email client. We have a...
New
kszambelanczyk
Hello! Could someone please give me a help/sample code, how to delete a file from s3 using waffle/waffle_ecto from Phoenix app. I creat...
New
RemyXRenard
I’m seeing that a list inside a Kino.DataTable will be interpreted as a charlist, even if the Kino.configure() is set to charlists: :as_l...
New
velrest
So my question is quite simple and i have found no conclusive answer on forum, google or AI. Should we use :erlang.float for Integer to ...
New
samoloth
Hi, I’ve just set up an application with ash_authentication. There is only magic link strategy for now, so there is no confirmation add o...
New
FlyingNoodle
If a change or preparation module uses Ash.Changeset.get_argument/2 or Ash.Query.get_argument/2 (or any of the other get_argument functio...
New
ryanwinchester
apply_graft/2 doesn’t rewrite an add_many sub-workflow’s deps on an add step. Grafted jobs cancel with “upstream job was deleted” Version...
New

Other Trending Topics Top

mudasobwa
I am happy to introduce the very α version of the new programming language compiled to BEAM. Welcome Cure. It has literally three kille...
New
garrison
Hobbes is a low-level distributed database for the Elixir programming language. Hobbes provides a simple, safe, and scalable storage lay...
New
marciok
Hi there! We created Gust: A task orchestrator inspired by Airflow. For those who have never heard about Aiflow, it’s a Python-based wor...
New
jimsynz
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
Dmk
Xamal is a deployment tool for Elixir apps that deploys native releases to bare metal servers over SSH. It’s a port of GitHub - basecamp/...
New
Damirados
Hello everyone. After busy few months I am happy to announce v0.1.0 of Emerge & Solve. They are GUI (Emerge) and State management (S...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews