How To Query A Dictionary In Python

Python is a powerful and versatile programming language that makes it easy to work with various data structures, such as dictionaries. In this tutorial, we will discuss what a dictionary is and how to query a dictionary in Python.

What is a Dictionary in Python?

A dictionary is an unordered collection of key-value pairs, where each key is unique. Dictionaries can be used for a wide variety of purposes, such as counting word frequencies, storing configuration settings, or representing a graph as an adjacency list. In Python, dictionaries are created using the dict keyword or curly braces {}.

Creating a Dictionary

Let’s create a simple dictionary that represents the number of fruits in a basket:

    fruits = {
        "apples": 4,
        "bananas": 6,
        "oranges": 2

Querying a Dictionary

There are several methods to query a dictionary in Python, which we will discuss in the following sections:

1. Using Square Bracket Notation

You can access the value associated with a specific key using square bracket notation. For example, to get the number of apples in the basket:

    apples = fruits["apples"]
    print(apples)  # Output: 4

Note that if the key does not exist in the dictionary, a KeyError will be raised. To avoid this, you can use the in keyword to check if a key is in the dictionary:

    if "apples" in fruits:
        apples = fruits["apples"]

2. Using the get() Method

Another way to query a dictionary is by using the get() method, which returns the value associated with a key if it exists, or a default value otherwise:

    apples = fruits.get("apples", 0)
    print(apples)  # Output: 4

3. Using the items() Method

The items() method returns a view object displaying a list of the dictionary’s key-value pairs. You can use this method to loop through the keys and values in the dictionary:

    for key, value in fruits.items():
        print(key, value)


    apples 4
    bananas 6
    oranges 2


In this tutorial, we have discussed what a dictionary is and how to query a dictionary in Python using various methods. By understanding these concepts, you can effectively work with dictionaries in your Python projects.