Python Dictionary pop() method

Python Dictionary pop() method

The dictionary.pop() method in removes the specified item and returns an element from a dictionary having the given key.

Syntax

dictionary.pop(key[, default])

Parameter

key – This argument signifies the key which is to be searched for removal.

default – This parameter represents the value which is to be returned when the key is not in the dictionary.

Return

This method removes and returns an element from a dictionary if the key is found else a KeyError exception is raised if the key if not found and the default argument is not specified.

Example 1

 # Python program explaining
 # the dictionary.pop() method
 # initialising the dictionary
 fruits = {
  "banana" : "apple",
   "orange": "mango",
   "grapes": 5
 }
 # printing the Dictionary
 print("Dictionary:",fruits)
 # removing the "banana" element from the dictionary.
 leftFruit=fruits.pop("banana")
 print("My final lists of fruits are\n", fruits) 

Output

 Dictionary: {'banana': 'apple', 'grapes': 5, 'orange': 'mango'}
 My final lists of fruits are
  {'grapes': 5, 'orange': 'mango'} 

Example 2

 # Python program explaining
 # the dictionary.pop() method
 # initializing dictionary  
 dictionary = { "Saturday" : 6, "Friday" : 5, "Monday" : 1,"Tuesday": 2 } 
 # Printing the specified dictionary 
 print ("The dictionary before deletion : " + str(dictionary)) 
 # using pop to return and remove key-value pair 
 # provided default 
 popValue = dictionary.pop('Friday', 5) 
 # Printing the value co-linked with the specified popped key  
 print ("Value linked with poppped key is : " + str(popValue)) 
 # using pop to return and remove key-value pair 
 # not provided default 
 popValue = dictionary.pop('Friday') 
 # Printing the value associated to popped key  
 # KeyError 
 print ("Value linked to poppped key is : " + str(popValue)) 

Output

 The dictionary before deletion : {'Tuesday': 2, 'Monday': 1, 'Saturday': 6, 'Friday': 5}
 Value linked with poppped key is : 5
 Traceback (most recent call last):
   File "main.py", line 19, in <module>
     popValue = dictionary.pop('Friday') 
 KeyError: 'Friday' 

Example 3

 # Python program explaining
 # the dictionary.pop() method
 # initializing the fruits dictionary
 fruits = { 'apple': 2, 'orange': 3, 'grapes': 4 }
 # Poping an element that is not present from the dictionary, provided a default value
 popList = fruits.pop('pineapple', 'strawberry')
 print('The popped element is:', popList)
 print('The dictionary is:', fruits) 

Output

The popped element is: strawberry
The dictionary is: {'grapes': 4, 'apple': 2, 'orange': 3}