How do I rename keys in a Python dictionary efficiently?

Changing Key Names in Python Dictionaries

Renaming keys in a dictionary is a common task in Python programming. This guide explains how to efficiently update key names using two different methods.

Method 1: Two-Step Approach

1. Assign the value associated with the old key to a new key:

   dictionary[new_key] = dictionary[old_key]

2. Delete the old key from the dictionary:

   del dictionary[old_key]

Method 2: One-Step Approach

Combine both steps into a single line using the pop() method:

dictionary[new_key] = dictionary.pop(old_key)

This approach is useful when you don't need to access the old value after changing the key. However, it's important to note that it will raise a KeyError exception if the old key doesn't exist.

Example

Consider the following dictionary:

dictionary = {
    1: 'one',
    2: 'two',
    3: 'three'
}

To change the key of 'one' from 1 to 'ONE':

dictionary['ONE'] = dictionary.pop(1)

The resulting dictionary will be:

dictionary = {
    2: 'two',
    3: 'three',
    'ONE': 'one'
}

By following these methods, you can easily modify key names in Python dictionaries, maintaining the integrity and consistency of your data.

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