Below is my code for part a and b: The issue I am having is trying to code for part c: I would greatly appreciate some assistance...with this portion of the question.

C. Write a program that requests the name of a continent as input, and then displays the names (in descending order) of the five most densely populated U.N. member countries in that continent. Use the pickled binary file nationsDict.dat and the file nation.py created in part (a).

1. United Nations The file UN.txt gives data about the 193 members of the United Nations. Each line of the file contains four pieces of data about a countryname, continent, population (in millions), and land area (in square miles).

1. Create a class named Nation with four instance variables to hold the data for a country and a method named popDensity that calculates the population density of the country. Write a program that uses the class to create a dictionary of 193 items, where each item of the dictionary has the form: name of a country: Nation Object for that country

Use the file UN.txt to create the dictionary, and save the dictionary in a pickled binary file named nationsDict.dat. Also, save the class Nation in a file named nation.py.

#class for Nation

class Nation:

#constructor for Nation

def __init__(self, tCountry="", tc="", tp=0, ta=0):

#assign the value for four parameters

self.country = tCountry;

self.continent = tc;

self.population = tp;

self.area = ta;

#setter method for country

def setCountry(self, tCountry):

self.country = tCountry;

#getter method for country

def getCountry(self):

return self.country;

#setter method for continent

def setContinent(self, tc):

self.continent = tc;

#getter method for continent

def getContinent(self):

return self.continent;

#setter method for population

def setPopulation(self, tp):

self.population = tp;

#getter method for population

def getPopulation(self):

return self.population;

#setter method for area

def setArea(self, ta):

self.area = ta;

#getter method for area

def getArea(self):

return self.area;

#method for find popDensity

def popDensity(self):

density = (float(self.population)/float(self.area))*10000

return '{0:2f}'.format(density)

from nation import *

from nation import Nation

#main function

def main():

#handle the nations object

nations = {};

try:

#for opening the file

fr = open("UN.txt", "r");

#Reading data from file

for line in fr:

#Stripping new line character and splitting on comma

lc = (line.strip()).split(",");

#creating a object for nation class

na = Nation(lc[0], lc[1],float(lc[2]),float(lc[3]));

# Storing in dictionary

nations[lc[0]] = na;

#close file

fr.close();

#reat the countryName name from user

countryName = input("Enter a country: ");

#check the the given country name is found in dictionary or not

if countryName not in nations.keys():

print(" Sorry! The given country name is not found ");

else:

#display the corresponding continent, Population and

#Area for given country

print("Continent: %s " %(nations[countryName].getContinent()));

print("Population: {:,d} ".format(int(nations[countryName].getPopulation() * 1000000)));

print("Area: {:,.2f} square miles ".format(nations[countryName].getArea()));

print("Density: {0} millions per sq.miles ".format(nations[countryName].popDensity()));

#for exception

except Exception as e:

print(e);

#calling main function

main();

2. Write a program that requests the name of a U.N. Member country as input, and then displays information about the country as shown in fig. 7.20. Use the pickled binary file nationsDict.dat and the file nation.py created in part (a)