PynamoDB
A Pythonic interface for Amazon's DynamoDB.
DynamoDB is a great NoSQL service provided by Amazon, but the API is verbose.PynamoDB presents you with a simple, elegant API.
Useful links:
- See the full documentation at https://pynamodb.readthedocs.io/
- Ask questions in the GitHub issues
- See release notes at https://pynamodb.readthedocs.io/en/latest/release_notes.html
Installation
From PyPi:
$ pip install pynamodb
From GitHub:
$ pip install git+https://github.com/pynamodb/PynamoDB#egg=pynamodb
From conda-forge:
$ conda install -c conda-forge pynamodb
Basic Usage
Create a model that describes your DynamoDB table.
from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute
class UserModel(Model):
"""
A DynamoDB User
"""
class Meta:
table_name = "dynamodb-user"
email = UnicodeAttribute(null=True)
first_name = UnicodeAttribute(range_key=True)
last_name = UnicodeAttribute(hash_key=True)
PynamoDB allows you to create the table if needed (it must exist before you can use it!):
UserModel.create_table(read_capacity_units=1, write_capacity_units=1)
Create a new user:
user = UserModel("John", "Denver")
user.email = "djohn@company.org"
user.save()
Now, search your table for all users with a last name of 'Denver' and whosefirst name begins with 'J':
for user in UserModel.query("Denver", UserModel.first_name.startswith("J")):
print(user.first_name)
Examples of ways to query your table with filter conditions:
for user in UserModel.query("Denver", UserModel.email=="djohn@company.org"):
print(user.first_name)
for user in UserModel.query("Denver", UserModel.email=="djohn@company.org"):
print(user.first_name)
Retrieve an existing user:
try:
user = UserModel.get("John", "Denver")
print(user)
except UserModel.DoesNotExist:
print("User does not exist")
Upgrade Warning
The behavior of 'UnicodeSetAttribute' has changed in backwards-incompatible waysas of the 1.6.0 and 3.0.1 releases of PynamoDB.
See UnicodeSetAttribute upgrade docsfor detailed instructions on how to safely perform the upgrade.
Advanced Usage
Want to use indexes? No problem:
from pynamodb.models import Model
from pynamodb.indexes import GlobalSecondaryIndex, AllProjection
from pynamodb.attributes import NumberAttribute, UnicodeAttribute
class ViewIndex(GlobalSecondaryIndex):
class Meta:
read_capacity_units = 2
write_capacity_units = 1
projection = AllProjection()
view = NumberAttribute(default=0, hash_key=True)
class TestModel(Model):
class Meta:
table_name = "TestModel"
forum = UnicodeAttribute(hash_key=True)
thread = UnicodeAttribute(range_key=True)
view = NumberAttribute(default=0)
view_index = ViewIndex()
Now query the index for all items with 0 views:
for item in TestModel.view_index.query(0):
print("Item queried from index: {0}".format(item))
It's really that simple.
Want to use DynamoDB local? Just add a host name attribute and specify your local server.
from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute
class UserModel(Model):
"""
A DynamoDB User
"""
class Meta:
table_name = "dynamodb-user"
host = "http://localhost:8000"
email = UnicodeAttribute(null=True)
first_name = UnicodeAttribute(range_key=True)
last_name = UnicodeAttribute(hash_key=True)
Want to enable streams on a table? Just add a stream_view_type name attribute and specifythe type of data you'd like to stream.
from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute
from pynamodb.constants import STREAM_NEW_AND_OLD_IMAGE
class AnimalModel(Model):
"""
A DynamoDB Animal
"""
class Meta:
table_name = "dynamodb-user"
host = "http://localhost:8000"
stream_view_type = STREAM_NEW_AND_OLD_IMAGE
type = UnicodeAttribute(null=True)
name = UnicodeAttribute(range_key=True)
id = UnicodeAttribute(hash_key=True)
Features
- Python >= 3.6 support
- An ORM-like interface with query and scan filters
- Compatible with DynamoDB Local
- Supports the entire DynamoDB API
- Support for Unicode, Binary, JSON, Number, Set, and UTC Datetime attributes
- Support for Global and Local Secondary Indexes
- Provides iterators for working with queries, scans, that are automatically paginated
- Automatic pagination for bulk operations
- Complex queries
- Batch operations with automatic pagination
- Iterators for working with Query and Scan operations