Computer Science - Informatics Practices Class XI/XII Python Dictionary Solved Test  Part 5

Q1. Explain the following functions in reference to dictionary.

a. items()

b. keys()

c. values()

Q2. Write the output of the following:

a={1:10,2:20,3:30}

b={3:35,4:40}

print(a.items())

print(a.keys())

print(a.values())

Q3. Write a program to store details like book

number, author name and price in dictionary.

Q4. To delete an element from dictionary, we can

use either _______ statement of ______ method.

Q5. What is the difference between list and

dictionary?

Q6. Why list can not be used as keys in dictionary?

Q7. a={1:10,2.5:20,3:30,4:40,5:50}

Find errors in the following and write the correct

statement

1. a(6) = 60
2. a.len()
3. a.clears()
4. a.gets(3)
5. a.item()
6. a.valueS()
7. a.keyS()
8. a.del(4)
9. pop(4)

                 SOLUTIONS

Q1. Explain the following functions in reference

to dictionary.

a. items()

b. keys()

c. values()

Ans. a. items() : This method returns the content

of dictionary as a list of tuples having key-value

pairs.

 b. keys() : It returns the list of key values in

dictionary.

 c. values(): It returns the list of values from

dictionary.

Q2. Write the output of the following:

a={1:10,2:20,3:30}

b={3:35,4:40}

print(a.items())

print(a.keys())

print(a.values())

Ans. dict_items([(1, 10), (2, 20), (3, 30)])      dict_keys([1, 2, 3]) dict_values([10, 20, 30])

Q3. Write a program to store details like book

number, author name and price in dictionary.

Ans. b={}

n=int(input("Enter number of records to enter"))

for i in range(n):

bno=int(input("Enter book number"))

bn=input("Enter book name")

pr=int(input("Enter price"))

t=(bn,pr)

b[bno]=t

print(b)

Q4. To delete an element from dictionary, we can

use either _______ statement of ______ method.

Ans. del, pop()

Q5. What is the difference between list and

dictionary?

List	Dictionary
Elements are enclosed in square brackets	Elements are enclosed in curly braces
Index value is an integer only	Index value can be of any type.

Q6. Why list can not be used as keys in dictionary?

Ans. Because list are mutable.

Q7. a={1:10,2.5:20,3:30,4:40,5:50}

Find errors in the following and write the correct

statement

1. a(6) = 60
2. a.len()
3. a.clears()
4. a.gets(3)
5. a.item()
6. a.valueS()
7. a.keyS()
8. a.del(4)
9. pop(4)

Ans.

1. a[6]=60
2. len(a)
3. a.clear()
4. a.get(3)
5. a.items
6. a.values()
7. a.keys()
8. del a[4]
9. a.pop(4)