CPython

2 articles

Python 09 Sep 2026 12 min read

Attach to Running Python Processes with sys.remote_exec in Python 3.14

A production Python process can be healthy enough to stay alive while still being difficult to understand. Perhaps one thread appears stuck. Memory is growing but the application has no diagnostic endpoint. A profiler was not enabled before startup. Restarting the process would erase the state you need to inspect. Python 3.14 adds a new CPython capability for this situation: sys.remote_exec(). It lets one Python process request that a .py file be executed by another running CPython process. The target executes that file on its main thread at a safe execution point.

Python Python 3.14

Python 09 Sep 2026 11 min read

Attach pdb to Running Python Processes in Python 3.14

A Python service can misbehave without crashing. A worker may loop unexpectedly, a request may remain in an odd state, or a long-running process may hold data that is difficult to reproduce in a development environment. Historically, using pdb in that situation usually required planning ahead. You could add breakpoint() to the code, start the program under the debugger, or restart it with extra instrumentation. Those approaches are useful, but they do not help much when the interesting state already exists inside a running process.

Python Debugging