Python dict.get() vs dict[‘brackets’], which approach is better?

Using the .get() method on a dictionary is generally considered a better approach than using the direct dictionary indexing dictionary['key'] method because the .get() method provides a default value if the key is not found in the dictionary, whereas direct dictionary indexing raises a KeyError exception.

Here is an example:

my_dict = {'a': 1, 'b': 2, 'c': 3}

# Using direct dictionary indexing
print(my_dict['d'])  # Raises KeyError: 'd'

# Using .get() method
print(my_dict.get('d', 0))  # Returns 0 (default value)

In this example, using my_dict['d'] directly raises a KeyError because the key 'd' is not in the dictionary. On the other hand, using my_dict.get('d', 0) returns a default value of 0 because the key 'd' is not in the dictionary.

Using the .get() method can make your code more readable and robust because you don’t have to handle the exception manually. It can also help avoid errors that might occur if the dictionary is modified or if the key is misspelled.

What about Django?

Using the .get() method can be especially useful in Django when you are working with query parameters, which are often stored in a dictionary-like object called request.GET.

For example, suppose you want to get the value of a query parameter called page. You could use direct dictionary indexing like this:

page = request.GET['page']  # Raises KeyError if 'page' is not in the query parameters

However, if the page parameter is not in the query parameters, this will raise a KeyError and your code will crash. To handle this more gracefully, you could use the .get() method like this:

page = request.GET.get('page', 1)  # Returns a default value of 1 if 'page' is not in the query parameters

In this example, if the page parameter is not in the query parameters, the .get() method returns a default value of 1 instead of raising a KeyError. This can help prevent your code from crashing and make it more robust.

Using the .get() method with query parameters in Django is a common and recommended practice because it can help make your code more readable, robust, and less prone to errors.

This article is a part of the Django tips and tricks article