Tablecloth

Tablecloth is a dataset (data frame) manipulation API built on top of the tech.ml.dataset library. It provides a simplified, thread-first API for common data manipulation tasks, inspired by R solutions like dplyr, tidyr, and data.table.

Key Features:

• Simplified API: Focuses on dataset manipulation, leaving pipelines, datatypes, and ML to tech.ml.
• Unified Entry Point: Uses a single function dispatching on arguments for common operations.
• Grouped Datasets: group-by operations return a special kind of dataset containing subsets as a column. Most operations automatically recognize and process both regular and grouped datasets.
• Thread-first Friendly: Designed to work seamlessly with Clojure's thread-first macro (->).

Note: Tablecloth is an addition to tech.ml.dataset, not a replacement.

When you use tc/group-by, the resulting dataset is a special kind of dataset that contains the subsets created during the grouping process as a column.

Most Tablecloth operations are designed to be polymorphic: they recognize whether they are receiving a regular dataset or a grouped dataset and process the data accordingly. This allows you to chain operations like tc/aggregate or tc/order-by immediately after a grouping operation without manual subsetting.

Tablecloth is available in different versions depending on your tech.ml.dataset version:

• For tech.ml.dataset 7.x: Use the master branch.
• For tech.ml.dataset 4.x: Use version 4.04.

To use Tablecloth, require tablecloth.api as tc. The following example demonstrates loading a CSV, grouping by symbol and year, aggregating the mean price, ordering the results, and taking the top 10 rows.

(require '[tablecloth.api :as tc])

(-> "https://raw.githubusercontent.com/techascent/tech.ml.dataset/master/test/data/stocks.csv"
    (tc/dataset {:key-fn keyword})
    (tc/group-by (fn [row]
                    {:symbol (:symbol row)
                     :year (tech.v3.datatype.datetime/long-temporal-field :years (:date row))}))
    (tc/aggregate #(tech.v3.datatype.functional/mean (% :price)))
    (tc/order-by [:symbol :year])
    (tc/head 10))