Check if a Dictionary is Empty

1. The Challenge: Dictionary Validation

Create a function is_empty(dictionary) that returns True if a dictionary is empty, and False otherwise.

2. Why It Matters

Dictionaries are Python's key-value lookup data structure. Checking if a dictionary contains data before reading keys prevents runtime errors.

3. The Python Solution

An empty dictionary {} is falsy in Python. You can check not dictionary or len(dictionary) == 0:

def is_empty(dictionary):
    return len(dictionary) == 0

# Pythonic Truthiness Alternative
def is_empty_pythonic(dictionary):
    return not dictionary

# Testing our function
print(is_empty({}))                  # Output: True
print(is_empty({"a": 1}))            # Output: False
print(is_empty_pythonic({}))         # Output: True

4. Dictionary Truthiness Model

• {} (Length 0) evaluates to False in boolean context.
• Any dictionary containing 1+ keys evaluates to True.

5. Common Mistakes

• KeyError on Missing Keys: Attempting to read a missing key dict["key"] from an unverified dictionary raises a KeyError. Use dict.get("key", fallback) for safe property access!

6. Next Steps

Use dict.get() for safe property reads. Next, let's repeat list items N times!