package talon

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Module Talon_csvSource

CSV codec for Talon dataframes.

  (* From string *)
  let df = Talon_csv.of_string csv_text

  (* From file (streaming) *)
  let df =
    Talon_csv.read "data.csv"
      (* To file (streaming) *)
      Talon_csv.write "out.csv" df
Sourcetype dtype_spec = (string * [ `Float32 | `Float64 | `Int32 | `Int64 | `Bool | `String ]) list

Column type specifications. Columns not listed are auto-detected.

Sourceval of_string : ?sep:char -> ?names:string list -> ?na_values:string list -> ?dtype_spec:dtype_spec -> string -> Talon.t

of_string s parses CSV text into a dataframe. The first row is used as column names unless names is provided, in which case all rows are treated as data.

  • parameter sep

    delimiter character (default ',')

  • parameter names

    explicit column names; when given, all rows are data

  • parameter na_values

    strings treated as null (default [""; "NA"; "N/A"; "null"; "NULL"; "nan"; "NaN"])

  • parameter dtype_spec

    explicit column types; unspecified columns are auto-detected

Sourceval to_string : ?sep:char -> ?na_repr:string -> Talon.t -> string

to_string df serializes a dataframe to CSV text. The first row of the output is the column names.

  • parameter sep

    delimiter character (default ',')

  • parameter na_repr

    string for null values (default "")

Sourceval read : ?sep:char -> ?names:string list -> ?na_values:string list -> ?dtype_spec:dtype_spec -> string -> Talon.t

read path reads a CSV file into a dataframe, streaming line by line.

  • parameter sep

    delimiter character (default ',')

  • parameter names

    explicit column names; when given, all rows are data

  • parameter na_values

    strings treated as null

  • parameter dtype_spec

    explicit column types

Sourceval write : ?sep:char -> ?na_repr:string -> string -> Talon.t -> unit

write path df writes a dataframe to a CSV file, streaming row by row.

  • parameter sep

    delimiter character (default ',')

  • parameter na_repr

    string for null values (default "")