Every Reader has its own ModuleCompleter instance

Lib/_pyrepl/_module_completer.py

@@ -15,6 +15,11 @@
     from typing import Any, Iterable, Iterator, Mapping
 
 
+def make_default_module_completer() -> ModuleCompleter:
+    # Inside pyrepl, __package__ is set to '_pyrepl'
+    return ModuleCompleter(namespace={'__package__': '_pyrepl'})
+
+
 class ModuleCompleter:
     """A completer for Python import statements.
 

Lib/_pyrepl/readline.py

@@ -39,7 +39,7 @@
 from . import commands, historical_reader
 from .completing_reader import CompletingReader
 from .console import Console as ConsoleType
-from ._module_completer import ModuleCompleter
+from ._module_completer import ModuleCompleter, make_default_module_completer
 
 Console: type[ConsoleType]
 _error: tuple[type[Exception], ...] | type[Exception]
@@ -100,8 +100,7 @@
 class ReadlineConfig:
     readline_completer: Completer | None = None
     completer_delims: frozenset[str] = frozenset(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?")
-    # Inside pyrepl, __package__ is set to '_pyrepl'
-    module_completer: ModuleCompleter = ModuleCompleter(namespace={'__package__': '_pyrepl'})
+    module_completer: ModuleCompleter = field(default_factory=make_default_module_completer)
 
 @dataclass(kw_only=True)
 class ReadlineAlikeReader(historical_reader.HistoricalReader, CompletingReader):