Use SQLAlchemy ORMs to Access USPS Data in Python

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USPS Python Connector

Python Connector Libraries for USPS Data Connectivity. Integrate USPS with popular Python tools like Pandas, SQLAlchemy, Dash & petl.



The CData Python Connector for USPS enables you to create Python applications and scripts that use SQLAlchemy Object-Relational Mappings of USPS data.

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems effectively. With the CData Python Connector for USPS and the SQLAlchemy toolkit, you can build USPS-connected Python applications and scripts. This article shows how to use SQLAlchemy to connect to USPS data to query, update, delete, and insert USPS data.

With built-in optimized data processing, the CData Python Connector offers unmatched performance for interacting with live USPS data in Python. When you issue complex SQL queries from USPS, the CData Connector pushes supported SQL operations, like filters and aggregations, directly to USPS and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to USPS Data

Connecting to USPS data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

To authenticate with USPS, set the following connection properties.

  • PostageProvider: The postage provider to use to process requests. Available options are ENDICIA and STAMPS. If unspecified, this property will default to ENDICIA.
  • UseSandbox: This controls whether live or test requests are sent to the production or sandbox servers. If set to true, the Password, AccountNumber, and StampsUserId properties are ignored.
  • StampsUserId: This value is used for logging into authentication to the Stamps servers. This value is not applicable for Endicia and is optional if UseSandbox is true.
  • Password: This value is used for logging into Endicia and Stamps servers. If the postage provider is Endicia, this will be the pass phrase associated with your postage account. It is optional if UseSandbox is true.
  • AccountNumber: The shipper's account number. It is optional if UseSandbox is true.
  • PrintLabelLocation: This property is required to use the GenerateLabels or GenerateReturnLabels stored procedures. This should be set to the folder location where generated labels should be stored.

The Cache Database

Many of the useful task available from USPS require a lot of data. To ensure this data is easy to input and recall later, utilize a cache database to make requests. Set the cache connection properties in order to use the cache:

  • CacheLocation: The path to the cache location, for which a connection will be configured with the default cache provider. For example, C:\users\username\documents\uspscache

As an alternative to CacheLocation, set the combination of CacheConnection and CacheProvider to configure a cache connection using a provider separate from the default.

Follow the procedure below to install SQLAlchemy and start accessing USPS through Python objects.

Install Required Modules

Use the pip utility to install the SQLAlchemy toolkit:

pip install sqlalchemy

Be sure to import the module with the following:

import sqlalchemy

Model USPS Data in Python

You can now connect with a connection string. Use the create_engine function to create an Engine for working with USPS data.

engine = create_engine("usps:///?PostageProvider=ENDICIA& RequestId=12345& Password='abcdefghijklmnopqr'& AccountNumber='12A3B4C'")

Declare a Mapping Class for USPS Data

After establishing the connection, declare a mapping class for the table you wish to model in the ORM (in this article, we will model the Senders table). Use the sqlalchemy.ext.declarative.declarative_base function and create a new class with some or all of the fields (columns) defined.

base = declarative_base()
class Senders(base):
	__tablename__ = "Senders"
	FirstName = Column(String,primary_key=True)
	Phone = Column(String)
	...

Query USPS Data

With the mapping class prepared, you can use a session object to query the data source. After binding the Engine to the session, provide the mapping class to the session query method.

Using the query Method

engine = create_engine("usps:///?PostageProvider=ENDICIA& RequestId=12345& Password='abcdefghijklmnopqr'& AccountNumber='12A3B4C'")
factory = sessionmaker(bind=engine)
session = factory()
for instance in session.query(Senders).filter_by(SenderID="25"):
	print("FirstName: ", instance.FirstName)
	print("Phone: ", instance.Phone)
	print("---------")

Alternatively, you can use the execute method with the appropriate table object. The code below works with an active session.

Using the execute Method

Senders_table = Senders.metadata.tables["Senders"]
for instance in session.execute(Senders_table.select().where(Senders_table.c.SenderID == "25")):
	print("FirstName: ", instance.FirstName)
	print("Phone: ", instance.Phone)
	print("---------")

For examples of more complex querying, including JOINs, aggregations, limits, and more, refer to the Help documentation for the extension.

Insert USPS Data

To insert USPS data, define an instance of the mapped class and add it to the active session. Call the commit function on the session to push all added instances to USPS.

new_rec = Senders(FirstName="placeholder", SenderID="25")
session.add(new_rec)
session.commit()

Update USPS Data

To update USPS data, fetch the desired record(s) with a filter query. Then, modify the values of the fields and call the commit function on the session to push the modified record to USPS.

updated_rec = session.query(Senders).filter_by(SOME_ID_COLUMN="SOME_ID_VALUE").first()
updated_rec.SenderID = "25"
session.commit()

Delete USPS Data

To delete USPS data, fetch the desired record(s) with a filter query. Then delete the record with the active session and call the commit function on the session to perform the delete operation on the provided records (rows).

deleted_rec = session.query(Senders).filter_by(SOME_ID_COLUMN="SOME_ID_VALUE").first()
session.delete(deleted_rec)
session.commit()

Free Trial & More Information

Download a free, 30-day trial of the USPS Python Connector to start building Python apps and scripts with connectivity to USPS data. Reach out to our Support Team if you have any questions.