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.