CSV

parse_csv(x::AbstractString; kw...) -> Vector{NamedTuple}
parse_csv(x::Vector{UInt8}; kw...) -> Vector{NamedTuple}

Parse a CSV string x (or vector of UInt8) into a vector of dictionaries, where keys are column names and values are corresponding cell values.

Keyword arguments

• delimiter::AbstractString = ",": The delimiter that will be used in the parsed csv string.
• Other keyword arguments can be found in CSV.File

Examples

julia> csv = """
       "id","name","grade"
       1,"Fred",78.2
       2,"Benny",82.0
       """;

julia> parse_csv(csv)
2-element Vector{NamedTuple{(:id, :name, :grade), Tuple{String, String, String}}}:
 (id = "1", name = "Fred", grade = "78.2")
 (id = "2", name = "Benny", grade = "82.0")

CSVSyntaxError <: Exception

Exception thrown when a parse_csv fails due to incorrect CSV syntax or any underlying error that occurs during parsing.

Fields

• message::String: The error message.
• exception::Exception: The catched exception.

deser_csv(::Type{T}, x; kw...) -> Vector{T}

Creates a new object of type T and fill it with values from CSV formated string x (or vector of UInt8).

Keyword arguments kw is the same as in parse_csv.

Examples

julia> struct Data
           id::Int64
           name::String
           grade::Float64
       end

julia> csv = """
       "id","name","grade"
       1,"Fred",78.2
       2,"Benny",82.0
       """;

julia> deser_csv(Data, csv)
2-element Vector{Data}:
 Data(1, "Fred", 78.2)
 Data(2, "Benny", 82.0)

to_csv(data::Vector{T}; kw...) -> String

Uses data element values to make csv rows with fieldnames as columns headers. Type T may be a nested dictionary or a custom type. In case of nested data, names of resulting headers will be concatenate by "_" symbol using dictionary key-names or structure field names.

Keyword arguments

• delimiter::String = ",": The delimiter that will be used in the returned csv string.
• headers::Vector{String} = String[]: Specifies which column headers will be used and in what order.
• with_names::Bool = true: Determines if column headers are included in the CSV output (true to include, false to exclude).

Examples

Converting a vector of regular dictionaries with fixed headers order.

julia> data = [
           Dict("id" => 1, "name" => "Jack"),
           Dict( "id" => 2, "name" => "Bob"),
       ];

julia> to_csv(data, headers = ["name", "id"]) |> print
name,id
Jack,1
Bob,2

Converting a vector of nested dictionaries with custom separator symbol.

julia> data = [
           Dict(
               "level" => 1,
               "sub" => Dict(
                   "level" => 2,
                   "sub" => Dict(
                       "level" => 3
                   ),
               ),
           ),
           Dict(:level => 1),
       ];

julia> to_csv(data, separator = "|") |> print
level|sub_level|sub_sub_level
1|2|3
1||

Converting a vector of custom structures.

julia> struct Foo
           val::Int64
           str::String
       end

julia> data = [Foo(1, "a"), Foo(2, "b")]
2-element Vector{Foo}:
 Foo(1, "a")
 Foo(2, "b")

julia> to_csv(data) |> print
str,val
a,1
b,2