Deciding How to Use InterSystems IRIS with Python

The four client-server options use language SDKs that run Python outside of the InterSystems IRIS process.

1. DB-API: Implements a PEP 249–compliant direct interface with InterSystems databases through the DB-API driver.

2. pyODBC: Establishes an Open Database Connectivity (ODBC) connection to InterSystems IRIS through the ODBC driver.

3. Native API: Provides direct access to many InterSystems IRIS features from Python through the Native driver.

4. Python Gateway: Calls out to an external language server.

With Embedded Python, Python runs in the same process as InterSystems IRIS. Embedded Python provides the lowest latency out of all these options.

• You are developing external Python applications (for example, data processing, analytics, or web services) that need to connect to InterSystems IRIS over a standard interface.

• You prefer or require working entirely with Python, outside of the InterSystems IRIS environment.

• You want to leverage the standard Python database workflow, including connection objects, cursors, and SQL execution.

• You are integrating InterSystems IRIS with Python tools and frameworks that expect DB-API compatibility (for example, pandas, SQLAlchemy, ORMs, Flask, and Streamlit).

For more information, see Using the Python DB-API.

• You need to connect to older versions of InterSystems IRIS (prior to version 2022.1) that do not support the Python DB-API driver.

• You are working in an environment where ODBC is already in place and integration depends on existing Data Source Names (DSNs).

• Your workflow depends on a low-level, ODBC-based architecture, such as certain legacy reporting or business intelligence tools that are being accessed from Python.

For more information, see ODBC Support for Python and Node.js.

• You need direct access to InterSystems IRIS globals, bypassing SQL and object layers.

• You are building high-performance or low-latency data processing systems that benefit from schema-less access.

• You are developing Python applications that run outside of the InterSystems IRIS environment.

• Your use case involves non-relational data models, such as hierarchical structures or key-value stores.

For more information, see Introduction to the Native SDK for Python.

• You want InterSystems IRIS to initiate execution of external Python code that lives outside the database processes.

• You are integrating existing Python applications, scripts, or services into InterSystems IRIS business logic.

• Embedded Python is not available in your deployment, but Python functionality is still required.

• Your use case involves external systems or APIs that are best handled by Python but must be coordinated from within InterSystems IRIS.

• You want to build or extend interoperability productions using Python components.

For more information, see Working with External Languages.

The Production EXtension (PEX) framework is an important example of how the Python Gateway architecture is used in practice. PEX allows you to develop interoperability productions—InterSystems IRIS workflows that integrate systems with different message formats and protocols—using external languages such as Python. With PEX, you can implement business services, processes, and adapters in Python that run as separate services connected via the gateway. These Python components are invoked at runtime and communicate with other production elements through the PEX messaging system, enabling seamless integration with InterSystems IRIS interoperability productions.

For more information, see Introduction to the PEX Framework.

In this mode, you use the command irispython to call in to InterSystems IRIS. By running irispython myscript.py from the command line, your Python script runs in the same process with InterSystems IRIS, while your Python code remains separate from any ObjectScript code. This code separation allows you to use all your customary Python development practices: such as debuggers, linters, and syntax coloring tools.

In this mode, InterSystems IRIS calls out to Python. There are several ways to initiate Python from InterSystems IRIS, each with specific use cases, for example:

• Write a method in an InterSystems IRIS class using the keyword [ Language = python ]. This is useful when you have an existing InterSystems IRIS class and you want to add a simple method written in Python.

• Use the Import() method of the %SYS.PythonOpens in a new tab class in InterSystems IRIS. This is useful when you want to import a Python module from ObjectScript in order to perform a well-defined task.

• Launch the Python shell from the Terminal using the Shell() method of the %SYS.PythonOpens in a new tab class. This is useful for testing a few lines of Python code interactively from within the InterSystems IRIS environment.

For larger-scale Python development, InterSystems recommends calling in to InterSystems IRIS from a .py file using irispython.