Bug Description

, in pdb.print_stack_entry, line_prefix is used as a default argument:
def print_stack_entry(self, frame_lineno, prompt_prefix=line_prefix):

This causes the value to be bound at definition time (when the module is imported). Any subsequent assignment to pdb.line_prefix by the user is ignored by this function.

Fix

Change the default argument to None and assign it inside the function body.

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-141781: Fix pdb line prefix binding #141779