python dictionary add value if key exists

Title: Adding a Value to a Python Dictionary if the Key Exists
Introduction:
Python dictionaries are versatile data structures that allow you to store and manipulate key-value pairs efficiently. In some scenarios, you might need to add a value to a dictionary only if a specific key already exists. In this tutorial, we'll explore how to achieve this using Python.
Code Example:
Explanation:
Create a Sample Dictionary: We start by creating a sample dictionary called sample_dict with some initial key-value pairs.
Define the Function: The add_value_if_key_exists function takes three parameters - the target dictionary, the key to check, and the value to add. Inside the function, it checks if the key already exists in the dictionary. If it does, the function adds the specified value to the existing value for that key. If the key doesn't exist, it prints a message indicating that the key does not exist, and no value is added.
Test the Function: We then test the function with two cases. In Case 1, the key 'key2' exists in the dictionary, so the value is added to the existing value. In Case 2, the key 'key4' does not exist, so the function prints a message indicating that the key does not exist, and no value is added.
Conclusion:
This tutorial demonstrates a simple and effective way to add a value to a Python dictionary only if a specific key already exists. This approach can be useful in scenarios where you want to update existing values based on certain conditions.
ChatGPT