Table of content

• About Project
• Problem description
• Building
• Usage
• Input data format
• Testing
• License

About Project

Small tool for aggregating and grouping data. Written in Go, it mimics the functionality of my older data-explorer project, which was written in C++. Created to learn Go better, exercise TDD and have some fun.

Problem description

For given input data, allow calculating the average, minimum and maximum, taking into consideration the grouping column.

Building

First, you need to download the repo to your machine. Make sure you have Go installed and the version is greater or equal to 1.22. Having that done, use the following command to build:

go build cmd/data-explorer/data-explorer.go

When executed in the root directory of the repository, it should create a binary called data-explorer.

Usage

data-explorer file {avg,min,max} aggregation grouping
Where:

• file - name of file with data to load,
• {avg,min,max} - type of operation, use one of those,
• aggregation - name of column used for aggregating data,
• grouping - name of column used for grouping data.

Example usage:
data-explorer sample.txt avg score first_name

Example output:

Data loaded in 0.000000s
Operation completed in 0.000000s
Results:
map[dave:8 tamas:5.5 tim:8]

Input data format

Input data need to have the following structure:

<column 1 name>;<column 2 name>;<column 3 name>  
<column 1 type>;<column 2 type>;<column 3 type>  
<data 1 1>;<data 2 1>;<data 3 1> 
...  
<data 1 n>;<data 2 n>;<data 3 n> 

Where column type can be string or integer.

Example data:

first_name;age;movie_name;score
string;integer;string;integer
tim;26;inception;8
tim;26;pulp_fiction;8
tamas;44;inception;7
tamas;44;pulp_fiction;4
dave;0;inception;8
dave;0;ender's_game;8

A non-flexible format of data was used for simplicity of parsing.

Testing

To execute tests manually, open root directory of repository and run command:

go test -v ./...

It should generate similar output:

$ go test -v ./...
?   	data-explorer/cmd/data-explorer	[no test files]
=== RUN   TestCalculatorExecute
=== RUN   TestCalculatorExecute/Max_age_grouped_by_movie_name
=== RUN   TestCalculatorExecute/Max_score_grouped_by_movie_name

(...)

--- PASS: TestMakeQuery/Args_list_too_short,_avg_operation,_proper_columns. (0.00s)
--- PASS: TestMakeQuery/Proper_number_of_args,_avg_operation,_wrong_aggregate_column. (0.00s)
--- PASS: TestMakeQuery/Proper_number_of_args,_avg_operation,_wrong_grouping_column. (0.00s)

PASS
ok  	data-explorer/internal	0.004s

License

The project is distributed under the MIT License. See LICENSE for more information.