aldizh / grouping

Group csv data by matching criteria

Programming Exercise - Grouping

The goal of this exercise is to identify rows in a CSV file that may represent the same person based on a provided Matching Type (definition below).

The resulting program should allow us to test at least three matching types:

• one that matches records with the same email address
• one that matches records with the same phone number
• one that matches records with the same email address OR the same phone number

Guidelines

• Please DO NOT fork this repository with your solution
• Use any language you want, as long as it can be compiled on OSX
• Only use code that you have license to use
• Don't hesitate to ask us any questions to clarify the project

Resources

CSV Files

Three sample input files are included. All files should be successfully processed by the resulting code.

Matching Type

A matching type is a declaration of what logic should be used to compare the rows.

For example: A matching type named same_email might make use of an algorithm that matches rows based on email columns.

Interface

At a high level, the program should take two parameters. The input file and the matching type.

Output

The expected output is a copy of the original CSV file with the unique identifier of the person each row represents prepended to the row.

Solution approach

• Create a uniqueness map of the criteria based on columns
• Matching criteria will determine the key of the row entry on this map
• We will call this key personID
• Iterate through the rows
  • If there is a value for matching criteria (email/phone)
    • If it exists on our map tag with the same person ID
    • Otherwise tag with a new person ID
• Basically we only tag rows with a new personID that are unique by the criteria

Assumtions

• Accounting only for U.S numbers
• If there are multiple columns for same criteria such as email1 and email2 consider both
• File size < 10mb

Running the project

$ ruby init.rb

Libraries used

csv ruby library for working with csv files