Function python_module_member_mutation 

pub fn python_module_member_mutation(
    root: Node<'_>,
    source: &str,
    module: &str,
    member: &str,
    max_nodes: usize,
) -> Option<PythonModuleMemberMutation>

What in this file can replace module.member, or None when nothing can.

An imported module object is shared process-wide, and Python permits replacing one of its attributes (os.system = fake). A reviewed summary describes the standard-library implementation, not a value written over it, so a consumer that closes a call on that summary must first prove no workspace source can perform the replacement. Two evidence families refuse it, and both fail closed:

1. A write-shaped target – an assignment, an augmented assignment, or a del – whose attribute access resolves to the module. A statically named attribute refuses that member; setattr and every other dynamic form arrives through the escape rule below.
2. Any use of a name bound to the module outside its own import statement and its attribute-object position. An alias, a call argument, a return, or a subscript can carry the shared module object to a writer this walk cannot see, so the proof refuses every member instead of following the value. A read of sys.modules is refused for the same reason: it reaches every module object in the process.

A file that never binds the module proves the absence vacuously. The walk is iterative and bounded; exhausting the bound refuses every member.