Answer:
Check the explanation
Step-by-step explanation:
class CitiesAndCountries:
"""
This is the class which maintains a dictionary of the Countries with the cites in them.
"""
def __init__(self):
"""
Constructor for the class CitiesAndCountries.
It defines a dictionary to store the names of the countries and a list of the cities which are in them
Example of the the following dictionary when it is populated:
citiesandcountries = {"india":["bhopal", "mumbai", "nagpur"], "usa":["new york", "seatlle"]
Keeping the names in lowercase helps in search
"""
self.citiesandcountries = {} # This is the dictionary which stores the information
def add_country(self, country_name):
"""
The add_country function to add countries to our list.
:param country_name: Name of the country to add to the dictionary
:return: True if added to the dictionary, False if it is already present in the dictionary
"""
if country_name.lower() not in self.citiesandcountries.keys():
self.citiesandcountries[country_name.lower()] = [] # Storing the country name in lower case helps in
# searching
return True
else: # You could omit the else statement and directly return False, but it adds to readability.
return False
def add_city(self, country_name, city_name):
"""
This function adds the cities names to the dictionary corresponding to their countries.
:param country_name: Country to which the city belongs
:param city_name: Name of the city to be added
:return: True if the country is present in the dictionary and the city is added to the list, else False
"""
if country_name.lower() in self.citiesandcountries.keys():
self.citiesandcountries[country_name.lower()].append(city_name.lower())
return True
else:
return False
def find_city(self, city_name):
"""
This function is used to retrive a list of countries where the city with the given name is present
:param city_name: Name of the city.
:return: A list of all the countries where the city if present.
"""
countries_with_city = []
for country in self.citiesandcountries.keys():
if city_name.lower() in self.citiesandcountries[country]:
countries_with_city.append(country.title())
return countries_with_city