Python Dictionary update() method
Python Dictionary update() method updates the dictionary with the elements from another dictionary object or from an iterable of key/value pairs.
Syntax: dict.update([other])
Parameters: This method takes either a dictionary or an iterable object of key/value pairs (generally tuples) as parameters.
Returns: It doesn’t return any value but updates the Dictionary with elements from a dictionary object or an iterable object of key/value pairs.
Python Dictionary update() Example
Example #1: Update with another Dictionary
Python3
# Python program to show working# of update() method in Dictionary# Dictionary with three itemsDictionary1 = {'A': 'Geeks', 'B': 'For', }Dictionary2 = {'B': 'Geeks'}# Dictionary before Updationprint("Original Dictionary:")print(Dictionary1)# update the value of key 'B'Dictionary1.update(Dictionary2)print("Dictionary after updation:")print(Dictionary1) |
Output:
Original Dictionary:
{'A': 'Geeks', 'B': 'For'}
Dictionary after updation:
{'A': 'Geeks', 'B': 'Geeks'}Example #2: Update with an iterable
Python3
# Python program to show working# of update() method in Dictionary# Dictionary with single itemDictionary1 = {'A': 'Geeks'}# Dictionary before Updationprint("Original Dictionary:")print(Dictionary1)# update the Dictionary with iterableDictionary1.update(B='For', C='Geeks')print("Dictionary after updation:")print(Dictionary1) |
Output:
Original Dictionary:
{'A': 'Geeks'}
Dictionary after updation:
{'C': 'Geeks', 'B': 'For', 'A': 'Geeks'}Example #3: Python dictionary update value if the key exists
Python3
def checkKey(dict, key): if key in dict.keys(): print("Key exist, ", end =" ") dict.update({'m':600}) print("value updated =", 600) else: print("Not Exist")dict = {'m': 700, 'n':100, 't':500} key = 'm'checkKey(dict, key)print(dict) |
Output:
Key exist, value updated = 600
{'m': 600, 'n': 100, 't': 500}
