ex_csv

CSV for Elixir

Monthly Downloads: 594

Programming language: Elixir

License: MIT License

Tags: CSV    

Latest version: v0.1.3

README

ExCsv

Elixir CSV.

Note: Currently only supports parsing.

Usage

Parsing

Parsing a file gives you a ExCsv.Table struct:

File.read!("foo/bar.csv") |> ExCsv.parse
# => {:ok, %ExCsv.Table{...}}

(You can alse use ExCsv.parse!/1 which will raise an error instead of returning an {:error, err} tuple if parsing fails.)

If your CSV has headings, you can let the parser know up front:

{:ok, table} = File.read!("foo/bar.csv") |> ExCsv.parse(headings: true)
# => {:ok, %ExCsv.Table{...}}
table.headings
# => ["Person", "Current Age"]

Or you can use ExCsv.with_headings/1 afterwards:

{:ok, table} = File.read!("foo/bar.csv")
               |> ExCsv.parse!
               |> ExCsv.with_headings
# => %ExCsv.Table{...}
table.headings
# => ["Person", "Current"]

You can also change the set or change headings by using ExCsv.with_headings/2:

table = File.read!("foo/bar.csv")
        |> ExCsv.parse!
        |> ExCsv.with_headings(["name", "age"])
# => %ExCsv.Table{...}
table.headings
# => ["name", "age"]

If you need to parse a format that uses another delimiter character, you can set it as an option (note the single quotes):

table = File.read!("foo/bar.csv") |> ExCsv.parse!(delimiter: ';')
# => %ExCsv.Table{...}

Once you have a ExCsv.Table, you can use its headings and body directly -- or you enumerate over the table.

Enumerating

If your ExCsv.Table struct does not have headers, iterating over it will result in a list for each row:

table = File.read!("foo/bar.csv")
        |> ExCsv.parse!
        |> Enum.to_list
# [["Jayson", 23], ["Jill", 34], ["Benson", 45]]

If your table has headings, you'll get maps:

table = File.read!("foo/bar.csv")
        |> ExCsv.parse!(headings: true)
        |> ExCsv.with_headings([:name, :age])
        |> Enum.to_list
# [%{name: "Jayson", age: 23},
#  %{name: "Jill", age: 34},
#  %{name: "Benson", age: 45}]

You can build structs from the rows by using ExCsv.as/1 (if the headings match the struct attributes):

table = File.read!("foo/bar.csv")
        |> ExCsv.parse!(headings: true)
        |> ExCsv.with_headings([:name, :age])
        |> ExCsv.as(Person)
        |> Enum.to_list
# [%Person{name: "Jayson", age: 23},
#  %Person{name: "Jill", age: 34},
#  %Person{name: "Benson", age: 45}]

If the headings don't match the struct attributes, you can provide a mapping (of CSV heading name to struct attribute name) with ExCsv.as/2:

table = File.read!("books.csv")
        |> ExCsv.parse!(headings: true)
        |> ExCsv.as(Author, %{"name" => :title, "author" => :name})
        |> Enum.to_list
# [%Author{name: "John Scalzi", title: "A War for Old Men"},
#  %Author{name: "Margaret Atwood", title: "A Handmaid's Tale"}]

Contributing

Please fork and send pull requests (preferably from non-master branches), including tests (ExUnit.Case).

Report bugs and request features via Issues; PRs are even better!

License

The MIT License (MIT)

Copyright (c) 2014 CargoSense, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.