Instructions
  1. Create a new python file: phone_book_system.py
  2. Inside the file, create an empty dictionary: phone_book. If you do not know how to create an empty dictionary, look at page 94 Starting with an empty Dictionary  section.
  3. Continuously display the following menu and when user enter “exit”, stop the program.
    1. What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop):
  4. When user enter “1”, we should ask 2 questions to the user: name and phone number. After that add these 2 informations to the phone_book dictionary. The key would be name and value would be the phone number.
  5. When user enter “2”, ask user for name of the person he/she is trying to find the phone number. If the name exists in the dictionary key, then display the person’s phone number.
  6. When user enter “3”, the program will display all name and phone numbers inside the dictionary.
Expected Result
What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 1
Enter a name: Gamas
Enter the phone: 888-888-8888

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 2
Enter a name you are trying to find: Gamas
Gamas phone number is 888-888-8888.

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 1
Enter a name: John
Enter the phone: 777-777-7777

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 2
Enter a name you are trying to find: john
John phone number is 777-777-7777.

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 3
gamas - 888-888-8888
john - 777-777-7777

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): 12312

What do you want to do
1. Add a phone number
2. Find a phone number
3. List all phone numbers
Enter your selection (enter 'exit' to stop): exit
Thank you for using our Phone application.