prettytable

Crystal library that makes it easy to build simple text tables.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     prettytable:
       github: henrikac/prettytable
   

2. Run shards install

Usage

Basic example

require "prettytable"

# default initialize
# table = PrettyTable::Table.new
# table.set_headers(["id", "name", "age"])

# initialize + set_headers
table = PrettyTable::Table.new(["id", "name", "age"])

table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"]
]

puts table

will output

+----+-------------------+-----+
| id | name              | age |
+----+-------------------+-----+
|  1 | Melody Connolly   |  42 |
|  2 | Leslie Hutchinson |   1 |
|  3 | Codey French      |  58 |
+----+-------------------+-----+

Notes:

• Once headers has been set they cannot be re-set / updated.
• Rows cannot be added to the table before the headers has been set.

Ways to add rows to table

• #add_row(row : Array(String))
• #add_rows(rows : Array(Array(String)))
• #<<(row : Array(String))
• #<<(rows : Array(Array(String)))

Delete row

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
# headers can be set as above or later with #set_headers(headers : Array(String))
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"]
]

table.delete_row(1) # => ["2", "Leslie Hutchinson", "1"]

Get row/column

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"],
  ["4", "Lulu Sparkles", "23"]
]

# get row
table[0] # => ["1", "Melody Connolly", "42"]

# get rows
table[1..3] # => [
            #      ["2", "Leslie Hutchinson", "1"],
            #      ["3", "Codey French", "58"],
            #      ["4", "Lulu Sparkles", "23"]
            #    ]

# get column
table["name"] # => ["Melody Connolly", "Leslie Hutchinson", "Codey French"]

Add/remove a column

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"],
]

table.add_column("height", ["158", "163", "189"])

table.remove_column("id") # => ["1", "2", "3"]

Select multiple columns

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"]
]

puts table.select(["name", "age"])

will output

+-------------------+-----+
| name              | age |
+-------------------+-----+
| Melody Connolly   |  42 |
| Leslie Hutchinson |   1 |
| Codey French      |  58 |
+-------------------+-----+

Difference between two tables

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "John Doe", "31"],
  ["2", "Kelly Strong", "20"],
  ["3", "James Hightower", "58"],
  ["4", "Brian Muscle", "3"],
  ["5", "Lulu Sparkles", "28"]
]

other = PrettyTable::Table.new(["id", "name", "age"])
other << [
  ["1", "John Doe", "31"],
  ["2", "Kelly Strong", "20"],
  ["3", "James Hightower", "58"]
]

puts table - other

will output

+----+---------------+-----+
| id | name          | age |
+----+---------------+-----+
|  4 | Brian Muscle  |  42 |
|  5 | Lulu Sparkles |  58 |
+----+---------------+-----+

Sort a table

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "John Doe", "31"],
  ["2", "Kelly Strong", "20"],
  ["3", "James Hightower", "58"],
  ["4", "Brian Muscle", "3"],
  ["5", "Lulu Sparkles", "28"]
]

sorted_table_asc = table.sort("name")
sorted_table_desc = table.sort("name", false)
custom_sort = table.sort { |a, b| a[2] <=> b[2] }

Sorting a table will always return a new table.

To hash

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"]
]

table.to_h # => {
           #      "id" => ["1", "2", "3"],
           #      "name" => ["Melody Connoly", "Leslie Hutchinson", "Codey French"],
           #      "age" => ["42", "1", "58"]
           #    }

To JSON

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
]

table.to_json # => [{"id":"1","name":"Melody Connolly","age":"42"}]

To/From CSV

require "prettytable"

table = PrettyTable::Table.new(["id", "name", "age"])
table << [
  ["1", "Melody Connolly", "42"],
  ["2", "Leslie Hutchinson", "1"],
  ["3", "Codey French", "58"]
]

table.to_csv("./table.csv") # => saves the table to table.csv

# Load table from .csv
loaded_table = PrettyTable::Table.from_csv("./table.csv")
loaded_table.headers # => ["id", "name", "age"]

Contributing

1. Fork it (https://github.com/henrikac/prettytable/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Henrik Christensen - creator and maintainer