Task: Top rank per group
C++: #include <string>
#include <set>
#include <list>
#include <map>
#include <iostream>


struct Employee
{
    std::string Name;
    std::string ID;
    unsigned long Salary;
    std::string Department;
    Employee(std::string _Name = "", std::string _ID = "", unsigned long _Salary = 0, std::string _Department = "")
    : Name(_Name), ID(_ID), Salary(_Salary), Department(_Department)
    { }

    void display(std::ostream& out) const
    {
        out << Name << "\t" << ID << "\t" << Salary << "\t" << Department << std::endl;
    }
};


struct CompareEarners
{
    bool operator()(const Employee& e1, const Employee& e2)
    {
        return (e1.Salary > e2.Salary);
    }
};


typedef std::list<Employee> EMPLOYEELIST;



typedef std::set<Employee, CompareEarners> DEPARTMENTPAYROLL;

typedef std::map<std::string, DEPARTMENTPAYROLL> DEPARTMENTLIST;

void initialize(EMPLOYEELIST& Employees)
{
    
    Employees.push_back(Employee("Tyler Bennett", "E10297", 32000, "D101"));
    Employees.push_back(Employee("John Rappl", "E21437", 47000, "D050"));
    Employees.push_back(Employee("George Woltman", "E21437", 53500, "D101"));
    Employees.push_back(Employee("Adam Smith", "E21437", 18000, "D202"));
    Employees.push_back(Employee("Claire Buckman", "E39876", 27800, "D202"));
    Employees.push_back(Employee("David McClellan", "E04242", 41500, "D101"));
    Employees.push_back(Employee("Rich Holcomb", "E01234", 49500, "D202"));
    Employees.push_back(Employee("Nathan Adams", "E41298", 21900, "D050"));
    Employees.push_back(Employee("Richard Potter", "E43128", 15900, "D101"));
    Employees.push_back(Employee("David Motsinger", "E27002", 19250, "D202"));
    Employees.push_back(Employee("Tim Sampair", "E03033", 27000, "D101"));
    Employees.push_back(Employee("Kim Arlich", "E10001", 57000, "D190"));
    Employees.push_back(Employee("Timothy Grove", "E16398", 29900, "D190"));
}

void group(EMPLOYEELIST& Employees, DEPARTMENTLIST& Departments)
{
    
    for( EMPLOYEELIST::iterator iEmployee = Employees.begin();
         Employees.end() != iEmployee;
         ++iEmployee )
    {
        DEPARTMENTPAYROLL& groupSet = Departments[iEmployee->Department];

        
        groupSet.insert(*iEmployee);
    }
}

void present(DEPARTMENTLIST& Departments, unsigned int N)
{
    
    for( DEPARTMENTLIST::iterator iDepartment = Departments.begin();
         Departments.end() != iDepartment;
         ++iDepartment )
    {
        std::cout << "In department " << iDepartment->first << std::endl;
        std::cout << "Name\t\tID\tSalary\tDepartment" << std::endl;
        
        unsigned int rank = 1;
        for( DEPARTMENTPAYROLL::iterator iEmployee = iDepartment->second.begin();
             ( iDepartment->second.end() != iEmployee) && (rank <= N);
             ++iEmployee, ++rank )
        {
            iEmployee->display(std::cout);
        }
        std::cout << std::endl;
    }
}

int main(int argc, char* argv[])
{
    
    EMPLOYEELIST Employees;

    
    initialize(Employees);

    
    DEPARTMENTLIST Departments;

    
    
    group(Employees, Departments);

    
    present(Departments, 3);

    return 0;
}

Python: from collections import defaultdict
from heapq import nlargest
 
data = [('Employee Name', 'Employee ID', 'Salary', 'Department'),
        ('Tyler Bennett', 'E10297', 32000, 'D101'),
        ('John Rappl', 'E21437', 47000, 'D050'),
        ('George Woltman', 'E00127', 53500, 'D101'),
        ('Adam Smith', 'E63535', 18000, 'D202'),
        ('Claire Buckman', 'E39876', 27800, 'D202'),
        ('David McClellan', 'E04242', 41500, 'D101'),
        ('Rich Holcomb', 'E01234', 49500, 'D202'),
        ('Nathan Adams', 'E41298', 21900, 'D050'),
        ('Richard Potter', 'E43128', 15900, 'D101'),
        ('David Motsinger', 'E27002', 19250, 'D202'),
        ('Tim Sampair', 'E03033', 27000, 'D101'),
        ('Kim Arlich', 'E10001', 57000, 'D190'),
        ('Timothy Grove', 'E16398', 29900, 'D190')]
 
departments = defaultdict(list)
for rec in data[1:]:
    departments[rec[-1]].append(rec)
 
N = 3
format = " %-15s " * len(data[0])
for department, recs in sorted(departments.items()):
    print ("Department %s" % department)
    print (format % data[0])
    for rec in nlargest(N, recs, key=lambda rec: rec[-2]):
        print (format % rec)
    print('')