Batting Averages Backend Exercise

Batting average is simple and a common way to measure batter’s performance. Create an app that will ingest a raw CSV file with player statistics and provide will provide player rankings based on their batting performance.

Input

The application should take an input in form of a CSV file. The file will be comma separated CSV with headers. The headers that interest you are: “playerID”, “yearID”, “stint”, teamID”, “AB”, and “H”.

The application should also accept filter options:

Year
Team name
Year and Team name

When filter are present, the output should include only players that match the filter, sorted according to their batting average.

Expected output

Batting Average is calculated as: BA = H/AB (Hits / At Bats).

If the player has more stints in the season, calculate batting average for the whole season (across all stints), team names are comma separated in that case. Format the batting average to 3 decimals.

You can write a standalone command line app, or you can write a web API along with simple client.

The output should be like a following table:

+----------+--------+--------------+-----------------+
| playerID | yearId | Team name(s) | Batting Average |
+----------+--------+--------------+-----------------+
| ...                                                |
+----------------------------------------------------+

CSV files

The input CSV file is Batting.csv. This file includes "teamID", use the file Teams.csv to map "teamID" to a team's real name. You can process the teams file and have the data ready in your app to map out "teamID" to team names, it doesn't need to be uploaded from the user.

Guidelines

Use any of the major languages that can be run on OSX
The app can be command line or provide an API over HTTP with command line client
Do not fork this repo, create a clean one for a solution
Feel free to ask for any clarification

Installation

Ruby 2.6.6

bundle install

chmod +x ./bin/bat.rb

User Guide

bin/bat.rb -h

Usage: bat [options]
    -y, --year YEAR                  Filter by Year
    -t, --team NAME                  Filter by the Team name

filter by Year

bin/bat.rb -y 2019

filter by Team name

bin/bat.rb -t "San Diego Padres"

or use both

bin/bat.rb -y 2019 -t "San Diego Padres"

+-----------+--------+------------------+-----------------+
| playerID  | yearId | Team name(s)     | Batting Average |
+-----------+--------+------------------+-----------------+
| cordefr02 | 2019   | San Diego Padres | 0.333           |
| tatisfe02 | 2019   | San Diego Padres | 0.317           |
| strahma01 | 2019   | San Diego Padres | 0.286           |
| mejiafr01 | 2019   | San Diego Padres | 0.265           |
| hosmeer01 | 2019   | San Diego Padres | 0.265           |
| machama01 | 2019   | San Diego Padres | 0.256           |
| reyesfr01 | 2019   | San Diego Padres | 0.255           |
| matonph01 | 2019   | San Diego Padres | 0.25            |
| allenlo01 | 2019   | San Diego Padres | 0.25            |
| naylojo01 | 2019   | San Diego Padres | 0.249           |
| garcigr01 | 2019   | San Diego Padres | 0.248           |
| martini02 | 2019   | San Diego Padres | 0.244           |
| myerswi01 | 2019   | San Diego Padres | 0.239           |
| margoma01 | 2019   | San Diego Padres | 0.234           |
| francty01 | 2019   | San Diego Padres | 0.234           |
| mejiase01 | 2019   | San Diego Padres | 0.233           |
| uriaslu01 | 2019   | San Diego Padres | 0.223           |
...

save to file

bin/bat.rb -y 2019 > batting2019.txt

mpakus / batting

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