CODEWITHSUNDEEP
csvocaml
user1181523
user1181523

Reputation: 71

Ocaml CSV to Float List

I'm looking for the easiest way to turn a CSV file (of floats) into a float list. I'm not well acquainted with reading files in general in Ocaml, so I'm not sure what this sort of function entails.

Any help or direction is appreciated :)

EDIT: I'd prefer not to use a third party CSV library unless I absolutely have to.

Upvotes: 2

Views: 1192

Answers (2)

Gilles 'SO- stop being evil'
Gilles 'SO- stop being evil'

Reputation: 107829

If you don't want to include a third-party library, and your CSV files are simply formatted with no quotes or embedded commas, you can parse them easily with standard library functions. Use read_line in a loop or in a recursive function to read each line in turn. To split each line, call Str.split_delim (link your program with str.cma or str.cmxa). Call float_of_string to parse each column into a float.

let comma = Str.regexp ","
let parse_line line = List.map float_of_string (Str.split_delim comma line)

Note that this will break if your fields contain quotes. It would be easy to strip quotes at the beginning and at the end of each element of the list returned by split_delim. However, if there are embedded commas, you need a proper CSV parser. You may have embedded commas if your data was produced by a localized program in a French locale — French uses commas as the decimal separator (e.g. English 3.14159, French 3,14159). Writing floating point data with commas instead of dots isn't a good idea, but it's something you might encounter (some spreadsheet CSV exports, for example). If your data comes out of a Fortran program, you should be fine.

Upvotes: 3

Andrej Bauer
Andrej Bauer

Reputation: 2477

https://forge.ocamlcore.org/projects/csv/

Upvotes: 3

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