debugpy: Debug Python Programs with DAP Clients

Overview

debugpy implements the Debug Adapter Protocol (DAP) for Python 3, allowing compatible editor and debugger clients to control and inspect Python programs. It addresses the integration between a Python process and DAP-based debugging tools, supporting both launching a program under the debugger and attaching to an existing process.

The project is actively maintained, with regular commits and releases, and development spread across many contributors rather than concentrated in one person. It is a focused debugging component, not a standalone graphical debugger: you use it with a DAP client.

Key Features

• Launch Python scripts or modules with a debugger adapter listening for a client.
• Wait for a client to attach before allowing program execution to continue.
• Attach the debugger to a running Python process by its process ID.
• Start debugging from Python code with debugpy.listen() and optionally block with debugpy.wait_for_client().
• Pause at programmatic breakpoints using breakpoint() or debugpy.breakpoint().
• Trigger post-mortem debugging for a caught exception when a client is attached.
• Configure subprocess debugging and enable internal logs for troubleshooting.

Use Cases

• Python developers using an editor with DAP support can launch scripts and inspect execution without switching to a separate debugger interface.
• Teams investigating a service or long-running Python process can attach a compatible client to a process that is already running.
• Developers can add optional debugging hooks to scripts or applications, then pause execution when a client connects.
• A team diagnosing a caught exception can trigger a debugger stop to inspect the remaining traceback and evaluate expressions.

Getting Started

Run a script with the adapter listening locally:

python -m debugpy --listen localhost:5678 myfile.py

Connect a DAP-compatible client to the listening adapter. See the README and command-line reference for installation, options, and details.

License in Plain Words

No standard license was detected. Without a license, the default copyright rules apply: you may read the code, but not reuse it. Check the repository or ask the authors.

Alternatives

• PySnooper: PySnooper traces executed lines and local-variable changes, while debugpy provides interactive debugging through the Debug Adapter Protocol.

Considerations

A debugging adapter needs a compatible DAP client; debugpy itself is not a complete editor or graphical debugging experience. Listening on 0.0.0.0 allows connections on all interfaces, and the README warns that anyone able to connect to the port can execute arbitrary code in the debugged process, so remote access should be restricted to secure networks. The project has recent commits and releases, and its contributors are not highly concentrated, but issues may take time to close. The supplied repository metadata reports the license as NOASSERTION, while the README displays an MIT license badge and links to a license file, so verify the applicable terms before adoption.