Python Dictionary Update

Update Dictionary in Python

You already know that we can access key:value pairs of a Python Dictionary using key as index with the reference to dictionary. In the same way, you can assign a value to this keyed index to dictionary to update the value of key:value pair in this dictionary.

In this tutorial, we will learn how to Update Dictionary in Python.

Updating a Dictionary in Python can be any of the following.

• Update value in key:value pair of Dictionary
• Add new key:value pair to Dictionary
• Delete key:value pair of Dictionary

We will look into each of the above said scenarios using examples.

Update value in key:value pair of Dictionary

To update value in a Dictionary corresponding to a key, all you have to do is assign the value to the key indexed dictionary reference.

In the following program, we update the value in dictionary myDict for key foo.

myDict = {
	'foo':12,
	'bar':14
}

#update value for key 'foo'
myDict['foo'] = 56

print(myDict)

Output

{'foo': 56, 'bar': 14}

Add new key:value pair to Dictionary

To add new key:value pair to a Dictionary, you have to assign the value to the key-indexed dictionary reference.

In the following program, we add a new key:value pair 'moo':85 to the dictionary myDict.

myDict = {
	'foo':12,
	'bar':14
}

#add key:value to dictionary
myDict['moo'] = 85

print(myDict)

Output

{'foo': 12, 'bar': 14, 'moo': 85}

Delete key:value pair of Dictionary

To delete key:value pair in a Dictionary, you can use del keyword with dictionary[key] as shown in the following program.

myDict = {
	'foo':12,
	'bar':14,
	'moo':85
}

#del key:value pair from dictionary
del myDict['foo']

print(myDict)

Output

{'bar': 14, 'moo': 85}

Summary

In this tutorial of Python Examples, we learned how to update Dictionary in Python, with the help of well detailed example programs.