Grouping Dictionaries

The Problem

Sometimes, rather being a list of records, the data you’d like to iterate is a dictionary:

    "today": {
        "event": "Bought sausages"
    "yesterday": {
        "event": "Bought a train set"

To create a table with When and Event columns, we’ll use a specific dictionary grouper.

Code Sample

Note that the column set is grouped via ByKey. The path to the key name is read from ByKey.key() and a path that drills into the key’s value is built with the ByKey.value() function.

from rolumns import ByKey, Columns
from rolumns.renderers import RowsRenderer

data = {
    "today": {
        "event": "Bought sausages",
    "yesterday": {
        "event": "Bought a train set",

columns = Columns(ByKey())
columns.add("When", ByKey.key())
columns.add("Event", ByKey.value("event"))

renderer = RowsRenderer(columns)
rows = renderer.render(data)



 [['When',      'Event'],
  ['today',     'Bought sausages'],
  ['yesterday', 'Bought a train set']]