In this article, we will discuss how to merge two dictionaries in Python. We will also explore various ways to combine dictionaries and provide the best practices for merging dictionaries.

Merging dictionaries is a common operation in Python, especially when you need to combine two dictionaries to form a new dictionary. Dictionaries are an essential data structure in Python and are used to store data in key-value pairs. A dictionary can contain any number of key-value pairs, and each key in the dictionary is unique.

Understanding Dictionaries in Python

Before we dive into creating a program to merge two dictionaries, let’s first review what dictionaries are in Python. In Python, dictionaries are a type of collection that stores data in key-value pairs. Each key is unique, and the associated value can be of any data type. You can think of a dictionary as a real-world dictionary, where each word (key) has a definition (value).

Here’s an example of a dictionary in Python:

				
					my_dict = {"name": "John", "age": 30, "city": "New York"}

n the example above, we have a dictionary called my_dict that contains three key-value pairs. The keys are name, age, and city, and the values are "John", 30, and "New York", respectively.

Merging Two Dictionaries in Python

Now that we understand what a dictionary is in Python, let’s move on to merging two dictionaries. There are several ways to merge two dictionaries, but the most straightforward method is to use the update() method.

The update() method is a built-in Python method that updates one dictionary with the key-value pairs from another dictionary. If a key already exists in the first dictionary, the value for that key is updated with the value from the second dictionary.

Here’s an example of using the update() method to merge two dictionaries:

				
					dict1 = {"name": "John", "age": 30}
dict2 = {"city": "New York", "country": "USA"}

dict1.update(dict2)

print(dict1)

Output:

				
					{"name": "John", "age": 30, "city": "New York", "country": "USA"}

In the example above, we have two dictionaries, dict1 and dict2. We use the update() method to merge dict2 into dict1, and the resulting dictionary is stored in dict1. The output of the program shows the merged dictionary.

Using the ** Operator to Merge Dictionaries

Another way to merge two dictionaries in Python is to use the ** operator. This operator allows you to merge two dictionaries into a new dictionary without modifying the original dictionaries.

Here’s an example of using the ** operator to merge two dictionaries:

				
					dict1 = {"name": "John", "age": 30}
dict2 = {"city": "New York", "country": "USA"}

merged_dict = {**dict1, **dict2}

print(merged_dict)

Output:

				
					{"name": "John", "age": 30, "city": "New York", "country": "USA"}

In the example above, we use the ** operator to merge dict1 and dict2 into a new dictionary called merged_dict. The output of the program shows the merged dictionary.

In this article, we’ve shown you how to merge two dictionaries in Python. We’ve covered two methods: using the update() method and using the ** operator. Both methods are straightforward and efficient, and you can choose the one that best suits your needs.


Thanks for reading. Happy coding!