How to generate a UUID in Python

Python generates UUIDs with the built-in uuid module — no third-party package needed: uuid.uuid4() returns a random UUID in one line. All snippets below were run on Python 3.13.

The one-liner (UUID v4)

import uuid

my_id = uuid.uuid4()
print(my_id)        # 65e82210-1a2d-4011-a064-a6a60565aa41
print(str(my_id))   # same, as str
print(my_id.hex)    # 65e822101a2d4011a064a6a60565aa41 (no hyphens)

uuid4() is random (122 bits from os.urandom), cryptographically secure, and the right default for most use cases.

Every UUID version in Python

Version	Code	Notes
v4 (random)	`uuid.uuid4()`	Default choice
v7 (time-ordered)	`uuid.uuid7()`	Python 3.14+ (see below for older versions)
v1 (timestamp+node)	`uuid.uuid1()`	Leaks MAC address by default — avoid for new code
v5 (SHA-1 name-based)	`uuid.uuid5(uuid.NAMESPACE_DNS, "example.com")`	Deterministic — always `cfbff0d1-9375-5685-…`
v3 (MD5 name-based)	`uuid.uuid3(uuid.NAMESPACE_DNS, "example.com")`	Prefer v5 unless compatibility requires v3

UUID v7 on Python 3.13 and older

uuid.uuid7() landed in Python 3.14. On earlier versions, use the uuid6 package:

pip install uuid6

from uuid6 import uuid7
print(uuid7())   # 0198c2f1-6d8a-7cc3-...  (sortable by creation time)

Why bother? v7 IDs sort by creation time, which keeps database indexes compact — see our UUID v4 vs v7 comparison for the full reasoning.

Parsing and validating

import uuid

def is_valid_uuid(value: str) -> bool:
    try:
        uuid.UUID(value)
        return True
    except ValueError:
        return False

is_valid_uuid("550e8400-e29b-41d4-a716-446655440000")  # True
is_valid_uuid("not-a-uuid")                            # False

u = uuid.UUID("550e8400-e29b-41d4-a716-446655440000")
u.version   # 4
u.bytes     # 16 raw bytes — store this, not the 36-char string

UUID primary keys in Django and SQLAlchemy

# Django
import uuid
from django.db import models

class Order(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

# SQLAlchemy 2.x
import uuid
from sqlalchemy.orm import Mapped, mapped_column

class Order(Base):
    __tablename__ = "orders"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)

Note default=uuid.uuid4 passes the function, not a call — a classic bug is writing uuid.uuid4() and giving every row the same ID. For high-insert tables, consider a v7 default instead (PostgreSQL guide coming in this series).

Frequently asked questions

Does Python's uuid module support UUID v7?

Yes, from Python 3.14: uuid.uuid7() is built in. On older versions, install the uuid6 package from PyPI and call uuid6.uuid7().

How do I get a UUID without hyphens in Python?

Use the .hex attribute: uuid.uuid4().hex returns the 32-character hexadecimal string without hyphens.

Is uuid4() cryptographically secure?

Yes. CPython's uuid4() uses os.urandom() via the random bytes API, which is suitable for security-sensitive identifiers.

How do I validate a UUID string in Python?

Pass it to the uuid.UUID() constructor inside a try/except ValueError block. It raises ValueError for badly formed strings.

Need a UUID right now without opening a REPL? Use our free UUID generator — v1/v3/v4/v5/v7, bulk up to 1,000, entirely in your browser.