Question

#Write a function called population_density. The function #should take one parameter, which will be a list of #dictionaries. Each dictionary in the list will have three #key-value pairs: # # - name: the name of the country # - population: the population of that country # - area: the area of that country (in km^2) # #Your function should return the population density of all #the countries put together. You can calculate this by #summing all the populations, summing all the areas, and #dividing the total population by the total area. # #Note that the input to this function will look quite long; #don't let that scare you. That's just because dictionaries #take a lot of text to define. #Add your function here!

Answer 1

Answer:

def population_density(dictionary_list):

     """ this function calculates the population density of a list of countries"""

    total_population= 0

    total_area= 0

    for country in dictionary_list:

           total_population += country['population']

           total_area += country['area']

    population_density = total_population / total_area

    return population_density

Explanation:

In python, functions are defined by the "def" keyword and a dictionary is used to hold immutable data key and its value. The for loop is used to loop through the list of dictionaries and the values of the country data and extracted with bracket notation.