`uuid`

The Python uuid module provides a way to generate universally unique identifiers (UUIDs), which are 128-bit values used to uniquely identify information in computer systems. UUIDs are often used when a unique identifier is required, such as database keys or session IDs.

Here’s a quick example:

>>> import uuid

>>> uuid.uuid4()
UUID('12345678-1234-5678-1234-567812345678')

Key Features

Generates UUIDs using random, time-based, and name-based methods
Supports UUID versions 1, 3, 4, and 5
Parses and validates UUID strings and objects
Converts UUIDs to and from string representations
Integrates seamlessly with Python types and serialization
Guarantees uniqueness across space and time

Frequently Used Classes and Functions

Object	Type	Description
`uuid.UUID`	Class	Represents a UUID object
`uuid.uuid1()`	Function	Generates a UUID based on the host ID and current time
`uuid.uuid3()`	Function	Generates a name-based UUID using MD5 hashing
`uuid.uuid4()`	Function	Generates a random UUID
`uuid.uuid5()`	Function	Generates a name-based UUID using SHA-1 hashing
`uuid.getnode()`	Function	Returns the hardware address as a 48-bit integer
`uuid.NAMESPACE_DNS`	Class	Represents the DNS namespace constant for name-based UUIDs

Examples

Generating a name-based UUID using MD5 hashing:

>>> import uuid

>>> uuid.uuid3(uuid.NAMESPACE_DNS, "python.org")
UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

Common Use Cases

Generating unique identifiers for database entries
Creating unique session IDs for web applications
Ensuring uniqueness of identifiers in distributed systems
Tagging files, resources, or objects with unique IDs
Safely merging data from multiple sources
Implementing resource identifiers in network protocols
Supporting object tracking in logging or auditing systems

Real-World Example

Here’s an example of using the uuid module to generate a unique filename for an uploaded file in a web application. This approach helps prevent filename collisions:

>>> import uuid

>>> def generate_unique_filename(filename):
...     file_extension = filename.split(".")[-1]
...     unique_id = uuid.uuid4()
...     return f"{unique_id}.{file_extension}"
...

>>> generate_unique_filename("document.txt")
'3f6d2f0e-19a4-4e5b-8cb3-3c9b7f2c9db7.txt'

In this example, the uuid module generates a UUID to ensure that each uploaded file has a unique name, preventing any potential file overwrites.

uuid