1. You can update many keys on the same statement.
my_dict.update(other_dict)
In this case you don't have to know how many keys are in the other_dict. You'll just be sure that all of them will be updated on my_dict.
2. You can use any iterable of key/value pairs with dict.update
As per the documentation you can use another dictionary, kwargs, list of tuples, or even generators that yield tuples of len 2.
3. You can use the update method as an argument for functions that expect a function argument.
Example:
def update_value(key, value, update_function):
update_function([(key, value)])
update_value("k", 3, update_on_the_db) # suppose you have a update_on_the_db function
update_value("k", 3, my_dict.update) # this will update on the dict
W3Schools
w3schools.com › python › ref_dictionary_update.asp
Python Dictionary update() Method
The specified items can be a dictionary, or an iterable object with key value pairs. ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com · If you want to report an error, or if you want to make a suggestion, send us an e-mail: help@w3schools.com · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python Tutorial W3.CSS Tutorial Bootstrap Tutorial PHP Tutorial Java Tutorial C++ Tutorial jQuery Tutorial
Top answer 1 of 3
50
1. You can update many keys on the same statement.
my_dict.update(other_dict)
In this case you don't have to know how many keys are in the other_dict. You'll just be sure that all of them will be updated on my_dict.
2. You can use any iterable of key/value pairs with dict.update
As per the documentation you can use another dictionary, kwargs, list of tuples, or even generators that yield tuples of len 2.
3. You can use the update method as an argument for functions that expect a function argument.
Example:
def update_value(key, value, update_function):
update_function([(key, value)])
update_value("k", 3, update_on_the_db) # suppose you have a update_on_the_db function
update_value("k", 3, my_dict.update) # this will update on the dict
2 of 3
22
d.update(n) is basically an efficient implementation of the loop
for key, value in n.items():
d[key] = value
But syntactically, it also lets you specify explicit key-value pairs without building a dict, either using keyword argumetns
d.update(a=1, b=2)
or an iterable of pairs:
d.update([('a', 1), ('b', 2)])
Videos
06:55
Python Basics: Updating Dictionaries Made Easy - YouTube
04:44
Updating and Adding Items in a Dictionary | Python Tutorial | Python ...
03:07
Python Dictionary - add and update items from a dictionary - YouTube
02:05
Python Dictionary Update() Method - YouTube
05:55
How to update a dictionary in Python | Python Dictionary Update ...
01:40
How to Update values in a Python Dictionary - YouTube
GeeksforGeeks
geeksforgeeks.org › python › python-dictionary-update-method
Python Dictionary update() method - GeeksforGeeks
February 16, 2026 - Example 1: In this example, new key-value pairs are added to the dictionary. ... Explanation: update({'y': 20}) adds new key 'y'.
Codecademy
codecademy.com › docs › python › dictionaries › .update()
Python | Dictionaries | .update() | Codecademy
May 13, 2025 - Updates the dictionary with key-value pairs from another dictionary or iterable, overwriting existing keys if they exist.
Reddit
reddit.com › r/learnpython › here's a quick way to update a dictionary with a second dictionary: use the '|=' operator.
r/learnpython on Reddit: Here's a quick way to update a dictionary with a second dictionary: use the '|=' operator.
May 27, 2023 -
for example, you have a dictionary 'DictA' and you want to update it with all the items from 'DictB'. Instead of looping on the keys, or items of DictB, you can simply:
DictA |= DictB
I use this A LOT, and I'm thankful to the Redditor who mentioned it in one of those long 'share your tips' threads...
Top answer 1 of 5
31
This is cool and nice to know about, but frankly DictA.update(DictB) is better IMHO. The result is exactly the same, but it’s more readable / less opaque and arcane. Even Pythonistas who have never heard of dict.update can probably guess what it does, unlike |= which you already have to be in-the-know about. dict.update is probably more backwards compatible too, though I’m less certain about this.
2 of 5
20
It' called the in-place union operator, it updates a dictionary in place. There's also the union operator dict1 | dict2 which merges two dictionaries merged = dict1 | dict2
GeeksforGeeks
geeksforgeeks.org › python › python-update-dictionary-with-other-dictionary
Update Dictionary with other Dictionary - Python - GeeksforGeeks
July 12, 2025 - Explanation: a[key] = b[key] for each key in b, its corresponding value in a is updated. If the key exists in a, its value is replaced with the value from b. This method involves manually looping through the second dictionary and checking whether ...
Python
docs.python.org › 3 › library › collections.html
collections — Container datatypes
This module implements specialized container datatypes providing alternatives to Python’s general purpose built-in containers, dict, list, set, and tuple. Added in version 3.3. A ChainMap class is provided for quickly linking a number of mappings so they can be treated as a single unit. It is often much faster than creating a new dictionary and running multiple update() calls.
Python Central
pythoncentral.io › python-dictionary-update-method-how-to-add-change-or-modify-values
Python Dictionary Update() Method: How To Add, Change, Or Modify Values | Python Central
January 30, 2024 - This article discusses how you can use the update() function to modify the keys of dictionaries.
Career Karma
careerkarma.com › blog › python › python dictionary update
Python Dictionary Update: A Complete Guide | Career Karma
December 1, 2023 - This allows us to update new_stock to be equal to True in our book dictionary. Finally, we print out our revised dictionary using print(book). The Python dictionary update() method allows you to update the contents of a dictionary.
Programiz
programiz.com › python-programming › methods › dictionary › update
Python Dictionary update()
The update() method updates the dictionary with the elements from another dictionary object or from an iterable of key/value pairs.
Tutorialspoint
tutorialspoint.com › python › dictionary_update.htm
Python dictionary update() Method
The Python dictionary update() method is used to update the key-value pairs of a dictionary. These key-value pairs are updated from another dictionary or iterable like tuple having key-value pairs.
Learn By Example
learnbyexample.org › python-dictionary-update-method
Python Dictionary update() Method - Learn By Example
April 20, 2020 - The update() method updates the dictionary with the key:value pairs from another dictionary or an iterable, overwriting existing keys.
DEV Community
dev.to › nitinreddy3 › python-dictionaries-part-3-haj
Python Dictionaries - Update data, loop through 🐍 - DEV Community
January 4, 2023 - If you observe in the above example, the new key-value pair is added with the curly braces as an argument to the update method. If the key-value pair already exists in the dictionary then the value will be replaced and if the key-value pair does not exist then this method will create a new key-value pair.
Jobtensor
jobtensor.com › Tutorial › Python › en › Dictionary-Methods-update
Python Dictionary update(), Definition, Syntax, Parameters, Examples | jobtensor
The specified items can be a dictionary, or an iterable object with key value pairs. ... person = { "name": "Raymond", "age": 29, "country": "Japan" } person.update({"color": "brown"}) print(person)
iO Flood
ioflood.com › blog › python-update-dictionary
Python Update Dictionary: Methods and Usage Guide
January 30, 2024 - In this example, we have two dictionaries: original_dict and update_dict. We use dictionary comprehension to merge these two dictionaries into new_dict. The values from update_dict overwrite the values from original_dict for any common keys. Python also provides the | operator to merge two dictionaries.
Python Reference
python-reference.readthedocs.io › en › latest › docs › dict › update.html
update — Python Reference (The Right Way) 0.1 documentation
Required. Either another dictionary object or an iterable of key:value pairs (iterables of length two). If keyword arguments are specified, the dictionary is then updated with those key:value pairs.
DigitalOcean
digitalocean.com › community › tutorials › python-add-to-dictionary
How to Add and Update Python Dictionaries Easily | DigitalOcean
October 16, 2025 - In this article, you’ll learn different methods to add to and update Python dictionaries. You’ll learn how to use the Python assignment operator, the update() method, and the merge and update dictionary operators.
KDnuggets
kdnuggets.com › 2023 › 02 › update-python-dictionary.html
How to Update a Python Dictionary - KDnuggets
February 20, 2023 - Learn how to update a Python dictionary using the built-in dictionary method update(). Update an existing Python dictionary with key-value pairs from another Python dictionary or iterable.
Vultr Docs
docs.vultr.com › python › standard-library › dict › update
Python dict update() - Update Dictionary | Vultr Docs
November 8, 2024 - The update() method in Python dictionaries simplifies the process of modifying dictionaries by adding or updating entries. This method is versatile, allowing updates from another dictionary, iterable of pairs, or direct key-value arguments.
The Teclado Blog
blog.teclado.com › python-updating-dictionaries
Updating Python Dictionaries
October 26, 2022 - In this snippet post we look at the update method for dictionaries. We can use update to change several values at once or extend dictionaries with new keys.