Python hash() Function: Usage and Examples

Get the integer hash value of a hashable object using hash().

What You Will Learn

hash(value) supports efficient dictionary and set lookup for hashable types. Hashes can vary across processes for salted types such as str; they are not stable serialization IDs or cryptographic digests.

Use hashlib for secure deterministic content digests, not the built-in hash() function.

Step-by-Step Example

The example below makes the behavior visible with small input values that you can change safely.

value = ("invoice", 2026)
print(isinstance(hash(value), int))
print(hash(value) == hash(value))

How the Example Works

The variable value holds the result of ('invoice', 2026). Later lines use that value or inspect how it changes.
The print() calls make the return values or state visible so you can compare them with the explanation and check your prediction.

Expected output from the example:

True
True

Another Example: Compare the Results

Try a second input and compare it with the first. Notice whether the result changes in type, value, order, or number of items.

print(hash(42) == hash(42))
print(hash((1, 2)) == hash((1, 2)))

Expected output:

True
True

When You Would Use This

These tools are useful when composing small reusable functions, adapting callbacks, or eliminating repeated work. Pay attention to whether the operation returns a new object, updates state, or produces lazy results. Test a small success case and a boundary case before integrating it into an application.

Practice: Modify the Code

Compare the hashes of equal tuples within one process.

Verify the changed output against the behavior described above, including the relevant invalid or boundary case.

For complete parameters and version details, consult the official Python documentation.

Common Beginner Mistakes

Using hash() for persistent checksums or secure password storage.
Calling hash() on mutable unhashable objects such as a list or dict.

Key Takeaways

Get the integer hash value of a hashable object using hash().
hash(value) supports efficient dictionary and set lookup for hashable types.
Use hashlib for secure deterministic content digests, not the built-in hash() function.