Quick Tip: `dict.setdefault()` eliminates boilerplate key checks

Quick Tip: dict.setdefault() eliminates boilerplate key checks

When working with dictionaries in Python, it's common to encounter situations where you need to check if a key exists before attempting to access or modify its value. Traditionally, this has been done using an if statement to check if the key is present in the dictionary. However, this approach can lead to boilerplate code and make your scripts less readable.

Before: Manual key check

d = {'a': 1, 'b': 2}

if 'c' not in d:
    d['c'] = []
d['c'].append(3)

As you can see, this approach requires an explicit check for the key's

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