Python - Remove Dictionary Items



Remove Dictionary Items Using del Keyword

Python's del keyword deletes any object from the memory. Here we use it to delete a key-value pair in a dictionary.

Syntax

del dict['key']

Example

numbers = {10:"Ten", 20:"Twenty", 30:"Thirty",40:"Forty"}
print ("numbers dictionary before delete operation: \n", numbers)
del numbers[20]
print ("numbers dictionary before delete operation: \n", numbers)

It will produce the following output

numbers dictionary before delete operation:
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty', 40: 'Forty'}
numbers dictionary before delete operation:
 {10: 'Ten', 30: 'Thirty', 40: 'Forty'}

Example

The del keyword with the dict object itself removes it from memory.

numbers = {10:"Ten", 20:"Twenty", 30:"Thirty",40:"Forty"}
print ("numbers dictionary before delete operation: \n", numbers)
del numbers
print ("numbers dictionary before delete operation: \n", numbers)

It will produce the following output

numbers dictionary before delete operation:
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty', 40: 'Forty'}
Traceback (most recent call last):
 File "C:\Users\mlath\examples\main.py", line 5, in <module>
  print ("numbers dictionary before delete operation: \n", numbers)
                                                           ^^^^^^^
NameError: name 'numbers' is not defined

Remove Dictionary Items Using pop() Method

The pop() method of dict class causes an element with the specified key to be removed from the dictionary.

Syntax

val = dict.pop(key)

Return value

The pop() method returns the value of the specified key after removing the key-value pair.

Example

numbers = {10:"Ten", 20:"Twenty", 30:"Thirty",40:"Forty"}
print ("numbers dictionary before pop operation: \n", numbers)
val = numbers.pop(20)
print ("nubvers dictionary after pop operation: \n", numbers)
print ("Value popped: ", val)

It will produce the following output

numbers dictionary before pop operation: 
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty', 40: 'Forty'}
nubvers dictionary after pop operation: 
 {10: 'Ten', 30: 'Thirty', 40: 'Forty'}
Value popped:  Twenty

Remove Dictionary Items Using popitem() Method

The popitem() method in dict class doesn't take any argument. It pops out the last inserted key-value pair, and returns the same as a tuple

Syntax

val = dict.popitem()

Return Value

The popitem() method return a tuple contain key and value of the removed item from the dictionary

Example

numbers = {10:"Ten", 20:"Twenty", 30:"Thirty",40:"Forty"}
print ("numbers dictionary before pop operation: \n", numbers)
val = numbers.popitem()
print ("numbers dictionary after pop operation: \n", numbers)
print ("Value popped: ", val)

It will produce the following output

numbers dictionary before pop operation: 
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty', 40: 'Forty'}
numbers dictionary after pop operation: 
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty'}
Value popped:  (40, 'Forty')

Remove Dictionary Items Using clear() Method

The clear() method in dict class removes all the elements from the dictionary object and returns an empty object.

Syntax

dict.clear()

Example

numbers = {10:"Ten", 20:"Twenty", 30:"Thirty",40:"Forty"}
print ("numbers dictionary before clear method: \n", numbers)
numbers.clear()
print ("numbers dictionary after clear method: \n", numbers)

It will produce the following output

numbers dictionary before clear method: 
 {10: 'Ten', 20: 'Twenty', 30: 'Thirty', 40: 'Forty'}
numbers dictionary after clear method: 
 {}
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