Python Program to Create a Dictionary

Introduction

A dictionary in Python is a collection of key-value pairs where each key is associated with a value. Dictionaries are mutable, meaning they can be modified after their creation. This tutorial will guide you through creating a Python program that creates a dictionary, allowing you to store and access data efficiently.

Example:

• Input: {'name': 'John', 'age': 25, 'city': 'New York'}

• Output: {'name': 'John', 'age': 25, 'city': 'New York'}

• Input: {'brand': 'Ford', 'model': 'Mustang', 'year': 1964}

• Output: {'brand': 'Ford', 'model': 'Mustang', 'year': 1964}

Problem Statement

Create a Python program that:

• Takes key-value pairs as input from the user.
• Creates a dictionary using the provided key-value pairs.
• Displays the created dictionary.

Solution Steps

1. Take Input from the User: Use the input() function to get key-value pairs from the user.
2. Create the Dictionary: Use a loop or other method to add key-value pairs to the dictionary.
3. Display the Dictionary: Use the print() function to display the created dictionary.

Python Program

# Python Program to Create a Dictionary
# Author: https://www.rameshfadatare.com/

# Step 1: Initialize an empty dictionary
my_dict = {}

# Step 2: Get the number of key-value pairs
n = int(input("Enter the number of key-value pairs: "))

# Step 3: Add key-value pairs to the dictionary
for _ in range(n):
    key = input("Enter key: ")
    value = input("Enter value: ")
    my_dict[key] = value

# Step 4: Display the created dictionary
print(f"The created dictionary is: {my_dict}")

Explanation

Step 1: Initialize an Empty Dictionary

• An empty dictionary my_dict is initialized using curly braces {}. This will store the key-value pairs entered by the user.

Step 2: Get the Number of Key-Value Pairs

• The input() function is used to prompt the user to enter the number of key-value pairs they want to add to the dictionary. This input is converted to an integer and stored in the variable n.

Step 3: Add Key-Value Pairs to the Dictionary

• A for loop is used to iterate n times. In each iteration, the user is prompted to enter a key and a value, which are then added to the dictionary using my_dict[key] = value.

Step 4: Display the Created Dictionary

• The print() function is used to display the dictionary after all key-value pairs have been added.

Output Example

Example 1:

Enter the number of key-value pairs: 3
Enter key: name
Enter value: John
Enter key: age
Enter value: 25
Enter key: city
Enter value: New York
The created dictionary is: {'name': 'John', 'age': 25, 'city': 'New York'}

Example 2:

Enter the number of key-value pairs: 2
Enter key: brand
Enter value: Ford
Enter key: model
Enter value: Mustang
The created dictionary is: {'brand': 'Ford', 'model': 'Mustang'}

Example 3:

Enter the number of key-value pairs: 4
Enter key: country
Enter value: USA
Enter key: capital
Enter value: Washington D.C.
Enter key: population
Enter value: 331 million
Enter key: continent
Enter value: North America
The created dictionary is: {'country': 'USA', 'capital': 'Washington D.C.', 'population': '331 million', 'continent': 'North America'}

Conclusion

This Python program demonstrates how to create a dictionary by prompting the user for key-value pairs. Dictionaries are versatile data structures in Python, and understanding how to create and manipulate them is essential for handling structured data efficiently.