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   |            |            |           |



Note

This task is aimed in particular at programming languages that are used in data science and data processing, such as F#, Python, R, SPSS, MATLAB etc.



Related tasks

 CSV data manipulation
 CSV to HTML translation
 Read entire file
 Read a file line by line


#lang transd
 
MainModule: {
 
tbl: `1001,Hopper
4004,Wirth
3003,Kemeny
2002,Gosling
5005,Kurtz`,
 
tbl1: `
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`,
 
cols: `@key_PATIENT_ID:Int,
        LASTNAME:String,
        VISIT_DATE:DateTime,
        SCORE:Double,
        SCORE_AVG:Double,
        NUM_VISITS:Int`,
 
Record : typealias(Tuple<Int DateTime Double>()),
 
	_start: (λ (with base TSDBase()
		(load-table base tbl colNames: cols)
        (build-index base "PATIENT_ID")
 
        (with vizs Vector<Record>() 
            (load-table vizs tbl1 :mixedTypes fieldSep: "," rowSep: "\n" )
            (for viz in vizs do
                (tsd-query base 
                    :update set:
                (lambda PATIENT_ID Int() VISIT_DATE DateTime() 
                        SCORE Double() SCORE_AVG Double() NUM_VISITS Int()
                    (+= NUM_VISITS 1)
                    (set VISIT_DATE (get viz 1)) 
                    (set SCORE (+ SCORE (get viz 2)))
                    (set SCORE_AVG (/ SCORE NUM_VISITS)))
            where: (lambda PATIENT_ID Int() (eq PATIENT_ID (get viz 0))))
            ))
 
        (with cols ["PATIENT_ID","LASTNAME","VISIT_DATE","SCORE","SCORE_AVG"]
        (with recs (tsd-query base select: cols 
                as: [[Int(), String(), DateTime(), Double(), Double()]]
                where: (lambda PATIENT_ID Int() true)
                )
                (for i in cols do (textout width: 10 i "|")) (lout "")
                (for rec in recs do 
                    (for-each rec (λ i :Data() (textout width: 10 i "|" )))
                    (lout ""))
		))
	))
}