Merge and aggregate datasets

From Roseeta Code Merge and aggregate datasets Task

• Merge and aggregate two datasets as provided in .csv files into a new resulting dataset.

• Use the appropriate methods and data structures depending on the programming language.

• Use the most common libraries only when built-in functionality is not sufficient.

  • Note Either load the data from the .csv files or create the required data structures hard-coded.

patients.csv   file contents:

PATIENT_ID,LASTNAME
1001,Hopper
4004,Wirth
3003,Kemeny
2002,Gosling
5005,Kurtz

visits.csv   file contents:

PATIENT_ID,VISIT_DATE,SCORE
2002,2020-09-10,6.8
1001,2020-09-17,5.5
4004,2020-09-24,8.4
2002,2020-10-08,
1001,,6.6
3003,2020-11-12,
4004,2020-11-05,7.0
1001,2020-11-19,5.3

Create a resulting dataset in-memory or output it to screen or file, whichever is appropriate for the programming language at hand. Merge and group per patient id and last name, get the maximum visit date, and get the sum and average of the scores per patient to get the resulting dataset. Note that the visit date is purposefully provided as ISO format, so that it could also be processed as text and sorted alphabetically to determine the maximum date.

| PATIENT_ID | LASTNAME | LAST_VISIT |  SCORE_SUM | SCORE_AVG |
| 1001       |  Hopper  | 2020-11-19 |  17.4      | 5.80      |
| 2002       |  Gosling | 2020-10-08 |   6.8      | 6.80      |
| 3003       |  Kemeny  | 2020-11-12 |            |           |
| 4004       |  Wirth   | 2020-11-05 |  15.4      | 7.70      |
| 5005       |  Kurtz   |            |            |           |

Nushell Code

 $visits
  | join $patients PATIENT_ID
  | upsert SCORE {|row| if ($row.SCORE == '' ) { 0.00 } else { $row.SCORE } }
  | group-by PATIENT_ID LASTNAME --to-table
  | each {|row|
     let scores = ($row.items | get SCORE | compact
        | each {|s| $s | into float } )
     let last_date = ($row.items | get VISIT_DATE | compact | sort | last )
     {
       PATIENT_ID: $row.PATIENT_ID,
       LASTNAME: $row.LASTNAME,
       LAST_DATE: $last_date,
       SUM_SCORE: ($scores | math sum),
       AVG_SCORE: ($scores | math avg),
       CNT:       ($scores | length)
     }
  }
  | sort-by PATIENT_ID

Nushell Output

╭───┬────────────┬──────────┬────────────┬───────────┬───────────┬─────╮
│ # │ PATIENT_ID │ LASTNAME │ LAST_DATE  │ SUM_SCORE │ AVG_SCORE │ CNT │
├───┼────────────┼──────────┼────────────┼───────────┼───────────┼─────┤
│ 0 │ 1001       │ Hopper   │ 2020-11-19 │     17.40 │      5.80 │   3 │
│ 1 │ 2002       │ Gosling  │ 2020-10-08 │      6.80 │      3.40 │   2 │
│ 2 │ 3003       │ Kemeny   │ 2020-11-12 │      0.00 │      0.00 │   1 │
│ 3 │ 4004       │ Wirth    │ 2020-11-05 │     15.40 │      7.70 │   2 │
╰───┴────────────┴──────────┴────────────┴───────────┴───────────┴─────╯