Data representations and data formats — usage and using

#!/bin/sh
asciidoctor -b docbook5 -o - $1 | pandoc -f docbook -t rst -o $2

#!/bin/sh
asciidoctor -b docbook5 -o - $1 | pandoc -f docbook -t rst

[ins] In [20]: with open('Data/data06.yaml', 'r') as infile:
          ...:     data = yaml.full_load(infile)
          ...:
[ins] In [21]: pprint.pprint(data)
['test 1',
 {'name1': 'value1', 'name2': 'value2', 'name3': 'value3'},
 {'name4': 'value4', 'name5': 'value5', 'name6': 'value6'},
 [11, 22, 33],
 [44, 55, {'name7': 'value7', 'name8': 'value8'}, 66]]

[ins] In [25]: with open("junk01.yaml", 'w') as outfile:
          ...:     yaml.dump(data, outfile)
          ...:

[ins] In [6]: import json
[ins] In [7]: mymap = {"name": "lemon", "color": "yellow", "sizes": [12, 14, 16]}
[ins] In [8]: data = json.dumps(mymap)
[ins] In [9]: data
Out[9]: '{"name": "lemon", "color": "yellow", "sizes": [12, 14, 16]}'
[ins] In [10]: json.loads(data)
Out[10]: {'name': 'lemon', 'color': 'yellow', 'sizes': [12, 14, 16]}

[ins] In [1]: import csv
[ins] In [2]: infile = open('tmp10.csv', 'r')
[ins] In [3]: reader = csv.reader(infile)
[ins] In [4]: rows = list(reader)
[ins] In [5]: rows
Out[5]:
[['Device_Software_Image_Version', '11.12.20'],
 ['Device_Product', 'Catalyst'],
 ['Product_B_version', '1.1.2.1'],
 ...
 ['Device_hw_type', 'virtual appliance']]

defp deps do
[
  {:csv, "~> 2.3.1"},
]
end

defmodule Test24.CSV do

      @csvdata1 [
        ~w(dog cat bird),
        ~w(tomato radish squash),
        ~w(lemon orange tangerine),
        ~w(poppy sunflower phacelia),
      ]

  @doc """
  Write a few lines to a CSV file.

  Options:

  * :force -- If true, overwrite existing file.

  ## Examples

      iex> Test24.CSV.write_csv_file("data01.csv", force: true)
      :ok

      iex> Test24.CSV.write_csv_file("data01.csv")
      :ok

      iex> Test24.CSV.write_csv_file("data01.csv")
      {:error, "file data01.csv exists"}

  """
  @spec write_csv_file(String.t(), Keyword.t()) :: :ok | {:error, String.t()}
  def write_csv_file(out_file_path, opts \\ []) do
    if Keyword.get(opts, :force) != true and File.exists?(out_file_path) do
      {:error, "file #{out_file_path} exists"}
    else
      data1 = @csvdata1
      out_file = File.open!(out_file_path, [:write])
      data1
      |> CSV.encode
      |> Enum.each(fn line ->
        IO.write(out_file, line)
        #IO.puts("line: #{line}")
      end)
      File.close(out_file)
      :ok
    end
  end

  @doc """
  Read CSV lines from file.  Parse into fields.  Display them.

  ## Examples

      iex> Test24.CSV.read_csv_file("data01.csv")
      dog|cat|bird
      tomato|radish|squash
      lemon|orange|tangerine
      poppy|sunflower|phacelia
      :ok

      iex> Test24.CSV.read_csv_file("missing_file.csv")
      {:error, "file missing_file.csv not found"}

  """
  @spec read_csv_file(String.t()) :: :ok | {:error, String.t()}
  def read_csv_file(in_file_path) do
    if not File.exists?(in_file_path) do
      {:error, "file #{in_file_path} not found"}
    else
      in_file_path
      #|> Path.expand(__DIR__)
      |> File.stream!
      |> CSV.decode!
      |> Enum.each(fn line ->
        #IO.puts(line)
        #IO.inspect(line, label: "line")
        IO.puts(Enum.join(line, "|"))
      end)
      :ok
    end
  end

end

[ins] In [10]: import sqlite3
[ins] In [11]: con = sqlite3.connect('tmp01.db')
[ins] In [12]:
[ins] In [12]: cursor = con.execute('select * from samples')
[ins] In [13]: for row in cursor:
          ...:     print(row)
          ...:
('carrot', 25)
('tomato', 35)
('radish', 15)

defp deps do
  [
    {:sqlite, "1.1.0"},
  ]
end