Python dict.clear Method: Usage and Examples

A temporary cache must be reset after an import.

What You Need to Understand

dict.clear() removes every key-value entry from an existing dictionary. It operates in place and returns None.

When to Use It

A temporary cache must be reset after an import.

Step-by-Step Python Example

cache = {"A": 10, "B": 20}
reference = cache
print(cache.clear())
print(reference)

How the Example Works

The return value is None; the existing dictionary shared by both names is now empty.

Example Output

None
{}
0

A Second Example

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

settings = {"enabled": True}
settings.clear()
print(len(settings))

Important Behavior and Edge Cases

Reassigning cache = {} does not empty objects already referenced elsewhere.

Try It Yourself

Reset a settings dictionary and check its length.

Common Beginner Mistakes

• Reassigning cache = {} does not empty objects already referenced elsewhere.
• Using the wrong collection method for this operation without checking whether it mutates the object, returns a result, or raises on missing data.

Key Takeaways

• dict.clear() removes every key-value entry from an existing dictionary.
• The return value is None; the existing dictionary shared by both names is now empty.
• Reassigning cache = {} does not empty objects already referenced elsewhere.