my_data_transform.rb

require 'date'

def transform_age(age)
    if age < 21
        return "1->20"
    elsif age < 41
        return "21->40"
    elsif age < 66
        return "41->65"
    else
        return "66->99"
    end
end

def transform_email(email)
    return email.split("@")[1]
end

def transform_time_range(time)
    date = DateTime.parse(time, '%Y-%m-%d %H:%M:%S')
    if (date.hour < 12)
        return "morning"
    elsif (date.hour < 18)
        return "afternoon"
    else
        return "evening"
    end
end

def my_data_transform(data)
    result = []
    row = 0
    temp_arr = data.split(/\r\n/)
    for line in temp_arr
        values = line.split(",")
        if (row > 0)
            values[4] = transform_email(values[4])
            values[5] = transform_age(values[5].to_i)
            values[9] = transform_time_range(values[9])
        end
        row += 1
        result << (values.join(","))
    end
    return result
end
puts my_data_transform("Gender,FirstName,LastName,UserName,Email,Age,City,Device,Coffee Quantity,Order At\nMale,Carl,Wilderman,carl,wilderman_carl@yahoo.com,29,Seattle,Safari iPhone,2,2020-03-06 16:37:56\nMale,Marvin,Lind,marvin,marvin_lind@hotmail.com,77,Detroit,Chrome Android,2,2020-03-02 13:55:51\nFemale,Shanelle,Marquardt,shanelle,marquardt.shanelle@hotmail.com,21,Las Vegas,Chrome,1,2020-03-05 17:53:05\nFemale,Lavonne,Romaguera,lavonne,romaguera.lavonne@yahoo.com,81,Seattle,Chrome,2,2020-03-04 10:33:53\nMale,Derick,McLaughlin,derick,mclaughlin.derick@hotmail.com,47,Chicago,Chrome Android,1,2020-03-05 15:19:48\n")