stouputils.parallel.capturer module

class PipeWriter(conn: Any, encoding: str, errors: str)

Bases: object

A writer that sends data to a multiprocessing Connection.

class CaptureOutput(

encoding: str = 'utf-8',

errors: str = 'replace',

)

Bases: object

Utility to capture stdout/stderr from a subprocess and relay it to the parent’s stdout.

The class creates an os.pipe(), marks fds as inheritable (for spawn method), provides methods to start a listener thread that reads from the pipe and writes to the main process’s sys.stdout/sys.stderr, and to close/join the listener.

>>> capturer = CaptureOutput(encoding="utf-8", errors="replace")

>>> pass # send capturer object to subprocess
>>> capturer.redirect()  # Redirects sys.stdout/sys.stderr to the pipe

>>> pass # in parent process:
>>> #capturer.parent_close_write()  # Close parent's write end
>>> capturer.start_listener()      # Start listener thread to read from pipe
>>> ...                            # do other work
>>> capturer.join_listener(timeout=0.1)       # Wait for listener to finish (on EOF)

redirect() → None

Redirect sys.stdout and sys.stderr to the pipe’s write end.

parent_close_write() → None

Close the parent’s copy of the write end; the child’s copy remains.

start_listener() → None

Start a daemon thread that forwards data from the pipe to sys.stdout/sys.stderr.

join_listener(

timeout: float | None = None,

) → None

Wait for the listener thread to finish (until EOF).