Python Dictionary update() Method

Python update() method updates the dictionary with the key and value pairs. It inserts key/value if it is not present. It updates key/value if it is already present in the dictionary.

It also allows an iterable of key/value pairs to update the dictionary. like: update(a=10,b=20) etc.

Signature and examples of this method are given below.

Signature

Parameters

other: It is a list of key/value pairs.

Return

It returns None.

Let?s see some examples of update() method to understand it?s functionality.

Python Dictionary update() Method Example 1

It is a simple example to update the dictionary by passing key/value pair. This method updates the dictionary. See an example below.

Output:

Inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000}
Updated inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000, 'cooler': 50}

Python Dictionary update() Method Example 2

If element (key/value) pair is already presents in the dictionary, it will overwrite it. See an example below.

Output:

Inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000, 'cooler': 50}
Updated inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000, 'cooler': 50}
Updated inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000, 'cooler': 150}

Python Dictionary update() Method Example 3

The update() method also allows iterable key/value pairs as parameter. See, the example below two values are passed to the dictionary and it is updated.

Output:

Inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000}
Updated inventory: {'Fan': 200, 'Bulb': 150, 'Led': 1000, 'cooler': 50, 'switches': 1000}