Python all() Function: Usage and Examples

A small report summarizes a collection without creating additional indexing logic.

What You Need to Understand

all() returns true when every element is truthy, including an empty iterable. It works on an iterable and is often clearer than writing a manual accumulation or search loop.

When to Use It

A small report summarizes a collection without creating additional indexing logic.

Step-by-Step Python Example

answers = [True, True, False]
print(all(answers))
print(all([]))

How the Example Works

The first result is False because one item is false; the empty result is True.

Example Output

False
True
True

A Second Example

Compare this smaller variation with the main example, then experiment with your own values.

values = (value for value in [1, 2, 3])
print(all(values))

Important Behavior and Edge Cases

all([]) is True by definition (vacuous truth); check non-emptiness separately if required.

Try It Yourself

Adapt the values and predict the result, then verify it in Python.

Common Beginner Mistakes

all([]) is True by definition (vacuous truth); check non-emptiness separately if required.
Overlooking how an iterable is consumed, how element positions are chosen, or whether a function creates a new list.

Key Takeaways

all() returns true when every element is truthy, including an empty iterable.
The first result is False because one item is false; the empty result is True.
all([]) is True by definition (vacuous truth); check non-emptiness separately if required.