Python Program to Merge Two Dictionaries

1. Introduction

Merging dictionaries is a common operation in Python programming, especially when dealing with data aggregation or when settings from multiple sources need to be combined. A dictionary in Python is a collection of key-value pairs that allows you to store and retrieve data based on a key. Python provides straightforward ways to merge dictionaries, making it a powerful tool for data manipulation. This blog post will explore a simple Python program to merge two dictionaries, demonstrating the utility of dictionary operations in Python.

2. Program Steps

1. Define two dictionaries that you want to merge.

2. Merge the dictionaries using a method that combines them into a single dictionary.

3. Display the merged dictionary.

3. Code Program

# Step 1: Define two dictionaries
dict1 = {'a': 1, 'b': 2}
dict2 = {'b': 3, 'c': 4}

# Step 2: Merge the dictionaries
# In Python 3.5+, use the {**dict1, **dict2} syntax to merge dictionaries
merged_dict = {**dict1, **dict2}

# Step 3: Display the merged dictionary
print("Merged dictionary:")
print(merged_dict)

Output:

Merged dictionary:
{'a': 1, 'b': 3, 'c': 4}

Explanation:

1. The program begins by initializing two dictionaries, dict1 and dict2, each containing some key-value pairs. The keys in these dictionaries represent identifiers, and the values represent the data associated with these identifiers.

2. To merge the dictionaries, the program uses the {**dict1, **dict2} syntax, which is available in Python 3.5 and later. This syntax unpacks the key-value pairs from both dictionaries into a new dictionary. If the same key exists in both dictionaries, the value from the second dictionary (dict2) will overwrite the value from the first dictionary (dict1).

3. Finally, the program prints the merged dictionary, showing the combination of key-value pairs from both original dictionaries. In the output, it's noticeable that the value of the key 'b' from dict2 has overwritten the value of the key 'b' from dict1, demonstrating how conflicts between duplicate keys are resolved in the merging process.