Question

Write a program to input your friends’ names and their Phone Numbers and store them in the dictionary as the key-value pair. Perform the following operations on the dictionary:
a) Display the name and phone number of all your friends
b) Add a new key-value pair in this dictionary and display the modified dictionary
c) Delete a particular friend from the dictionary
d) Modify the phone number of an existing friend
e) Check if a friend is present in the dictionary or not
f) Display the dictionary in sorted order of names

Answer 1

Program:
dic = {}
#Creates an empty dictionary

#While loop to provide the options repeatedly
#it will exit when the user enters 7
while True:
print("1. Add New Contact")
print("2. Modify Phone Number of Contact")
print("3. Delete a Friend's contact")
print("4. Display all entries")
print("5. Check if a friend is present or not")
print("6. Display in sorted order of names")
print("7. Exit")
inp = int(input("Enter your choice(1-7): "))

#Adding a contact
if(inp == 1):
name = input("Enter your friend name: ")
phonenumber = input("Enter your friend's contact number: ")
dic[name] = phonenumber
print("Contact Added \n\n")
#Modifying a contact if the entered name is present in the dictionary
elif(inp == 2):
name = input("Enter the name of friend whose number is to be modified: ")
if(name in dic):
phonenumber = input("Enter the new contact number: ")
dic[name] = phonenumber
print("Contact Modified\n\n")
else:
print("This friend's name is not present in the contact list")
#Deleting a contact if the entered name is present in the dictionary
elif(inp == 3):
name = input("Enter the name of friend whose contact is to be deleted: ")
if(name in dic):
del dic[name]
print("Contact Deleted\n\n")
else:
print("This friend's name is not present in the contact list")
#Displaying all entries in the dictionary
elif(inp == 4):
print("All entries in the contact")
for a in dic:
print(a,"\t\t",dic[a])
print("\n\n\n")
#Searching a friend name in the dictionary
elif(inp == 5):
name = input("Enter the name of friend to search: ")
if(name in dic):
print("The friend",name,"is present in the list\n\n")
else:
print("The friend",name,"is not present in the list\n\n")
#Displaying the dictionary in the sorted order of the names
elif(inp == 6):
print("Name\t\t\tContact Number")
for i in sorted(dic.keys()):
print(i,"\t\t\t",dic[i])
print("\n\n")
#Exit the while loop if user enters 7
elif(inp == 7):
break
#Displaying the invalid choice when any other values are entered
else:
print("Invalid Choice. Please try again\n")

OUTPUT:

1. Add New Contact

2. Modify Phone Number of Contact

3. Delete a Friend's contact

4. Display all entries

5. Check if a friend is present or not

6. Display in sorted order of names

7. Exit

Enter your choice(1-7): 1

Enter your friend name: Mohit

Enter your friend's contact number: 98765*****

Contact Added

1. Add New Contact

2. Modify Phone Number of Contact

3. Delete a Friend's contact

4. Display all entries

5. Check if a friend is present or not

6. Display in sorted order of names

7. Exit

Enter your choice(1-7): 1

Enter your friend name: Mohan

Enter your friend's contact number: 98764*****

Contact Added

1. Add New Contact

2. Modify Phone Number of Contact

3. Delete a Friend's contact

4. Display all entries

5. Check if a friend is present or not

6. Display in sorted order of names

7. Exit

Enter your choice(1-7): 6

Name Contact Number

Mohan 98764*****

Mohit 98765*****

1. Add New Contact

2. Modify Phone Number of Contact

3. Delete a Friend's contact

4. Display all entries

5. Check if a friend is present or not

6. Display in sorted order of names

7. Exit

Enter your choice(1-7): 7