Python - Swap ith and jth key’s value in dictionary

Python - Swap ith and jth key’s value in dictionary

Swapping the values of two keys in a dictionary is a useful operation when manipulating data structures in Python. This tutorial will guide you through the process of swapping the values of the ith and jth keys in a dictionary.

Objective:

Given a dictionary and two keys, i and j, we need to swap the values associated with these keys.

Example:

For the dictionary:

dict_data = { "a": 1, "b": 2, "c": 3, "d": 4 }

If we want to swap the values for keys "b" and "d", the resultant dictionary would be:

{ "a": 1, "b": 4, "c": 3, "d": 2 }

Step by Step Tutorial:

  • Understanding the Problem:

    • We are given a dictionary and two keys, i and j.
    • We need to swap the values associated with these keys.

  • Swapping Values:

    • Use a temporary variable to hold the value of the ith key.
    • Assign the value of the jth key to the ith key.
    • Assign the value in the temporary variable to the jth key.

Here's how you can do it:

i, j = "b", "d" # Swap using a temporary variable temp = dict_data[i] dict_data[i] = dict_data[j] dict_data[j] = temp
  • Display the Result:
print(dict_data)

Full Code:

dict_data = { "a": 1, "b": 2, "c": 3, "d": 4 } # Keys whose values need to be swapped i, j = "b", "d" # Swap using a temporary variable temp = dict_data[i] dict_data[i] = dict_data[j] dict_data[j] = temp # Print the resultant dictionary print(dict_data) # Output: {'a': 1, 'b': 4, 'c': 3, 'd': 2}

Tips and Tricks:

  • You can perform the swap in a more concise manner using tuple unpacking:

    dict_data[i], dict_data[j] = dict_data[j], dict_data[i]

Considerations:

  • Ensure that both keys, i and j, exist in the dictionary. If they don't, you'll encounter a KeyError. To avoid this, you might want to check if both keys exist before attempting the swap.
  • Remember that dictionaries in Python 3.7 and later versions maintain insertion order. So, the order of key-value pairs will remain consistent even after the swap. However, in earlier Python versions, dictionaries do not guarantee order.

And that's how you swap the values of two keys in a Python dictionary!

More Tags

rerender href avro vuforia genson performance-testing removing-whitespace electron-builder properties-file lidar

More Programming Guides

Other Guides

More Programming Examples