Class XI : Python Dictionary 5

How to delete or remove elements from a dictionary?

pop():

we can remove a particular item in a dictionary by using the method pop(). this method removes as item with the provided key and returns the value.

popitem():

the method, popitem() can be used to remove and return an arbitrary item (key, value) form the dictionary.

clear()

all the items can be removed at once using the clear() method.

del

we can also use the del keyword to remove individual items or the entire dictionary itself.

Example of pop():

Example:1

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}
print(squares)

# remove a particular item
print(squares.pop(4))
print(squares)

print(squares.pop(2))
print(squares)

Output:

{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
16
{1: 1, 2: 4, 3: 9, 5: 25}
4
{1: 1, 3: 9, 5: 25}

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}  
print(squares)

# remove a particular item
print(squares.pop(4))  
print(squares)

print(squares.pop(2))  
print(squares)
{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
16
{1: 1, 2: 4, 3: 9, 5: 25}
4
{1: 1, 3: 9, 5: 25}

Example:2

#student details

student={“roll”:101,”name”:”sumit”,”per”:98}
print(student)
# remove a particular item
print(student.pop(“name”))
print(student)
# remove a particular item
print(student.pop(“per”))
print(student)

Output:

{‘roll’: 101, ‘name’: ‘sumit’, ‘per’: 98}
sumit
{‘roll’: 101, ‘per’: 98}
98
{‘roll’: 101}
>>>

#student details

student={"roll":101,"name":"sumit","per":98}
print(student)
# remove a particular item
print(student.pop("name"))
print(student)
# remove a particular item
print(student.pop("per"))
print(student)
{'roll': 101, 'name': 'sumit', 'per': 98}
sumit
{'roll': 101, 'per': 98}
98
{'roll': 101}
>>> 

Example of popitem():

Example:1

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}
print(squares)

# remove a particular item
print(squares.popitem())
print(squares)

print(squares.popitem())
print(squares)

Output:

{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
(5, 25)
{1: 1, 2: 4, 3: 9, 4: 16}
(4, 16)
{1: 1, 2: 4, 3: 9}

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}  
print(squares)

# remove a particular item
print(squares.popitem())  
print(squares)

print(squares.popitem())  
print(squares)
{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
(5, 25)
{1: 1, 2: 4, 3: 9, 4: 16}
(4, 16)
{1: 1, 2: 4, 3: 9}

Example:2

#student details

student={“roll”:101,”name”:”sumit”,”per”:98}
print(student)
# remove a particular item
print(student.popitem())
print(student)
# remove a particular item
print(student.popitem())
print(student)

Output:

{‘roll’: 101, ‘name’: ‘sumit’, ‘per’: 98}
(‘per’, 98)
{‘roll’: 101, ‘name’: ‘sumit’}
(‘name’, ‘sumit’)
{‘roll’: 101}
>>>

#student details

student={"roll":101,"name":"sumit","per":98}
print(student)
# remove a particular item
print(student.popitem())
print(student)
# remove a particular item
print(student.popitem())
print(student)
{'roll': 101, 'name': 'sumit', 'per': 98}
('per', 98)
{'roll': 101, 'name': 'sumit'}
('name', 'sumit')
{'roll': 101}
>>> 

Example of clear():

Example:1

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}
print(squares)
print(squares.clear())
print(squares)

Output:

{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
None
{}
>>>

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}  
print(squares)
print(squares.clear())  
print(squares)
{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
None
{}
>>> 

Example:2

#student details

student={“roll”:101,”name”:”sumit”,”per”:98}
print(student)
print(student.clear())
print(student)

Output:

{‘roll’: 101, ‘name’: ‘sumit’, ‘per’: 98}
None
{}
>>>

#student details

student={"roll":101,"name":"sumit","per":98}
print(student)
print(student.clear())
print(student)
{'roll': 101, 'name': 'sumit', 'per': 98}
None
{}
>>> 

Example of del:

Example:1

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}
print(squares)
del squares
print(squares)
#error will be displayed as dictionary is deleted (not present)

# create a dictionary
squares = {1:1, 2:4, 3:9, 4:16, 5:25}  
print(squares)
del squares  
print(squares)
#error will be displayed as dictionary is deleted (not present)
{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
Traceback (most recent call last):
  File "E:\python\Dictionary\py_dic1.py", line 5, in <module>
    print(squares)
NameError: name 'squares' is not defined
>>> 

Example:2

#student details

student={“roll”:101,”name”:”sumit”,”per”:98}
print(student)
del student
print(student)
#error will be displayed as dictionary is deleted (not present)

Output:

{'roll': 101, 'name': 'sumit', 'per': 98}
Traceback (most recent call last):
  File "E:\python\Dictionary\py_dic1.py", line 7, in <module>
    print(student)
NameError: name 'student' is not defined
>>>