diff --git a/Lib/pdb.py b/Lib/pdb.py index 41735f4e249f5d..a990d60fe1c2fd 100755 --- a/Lib/pdb.py +++ b/Lib/pdb.py @@ -332,14 +332,6 @@ def __init__(self, completekey='tab', stdin=None, stdout=None, skip=None, except ImportError: pass - # GH-138860 - # We need to lazy-import rlcompleter to avoid deadlock - # We cannot import it during self.complete* methods because importing - # rlcompleter for the first time will overwrite readline's completer - # So we import it here and save the Completer class - from rlcompleter import Completer - self.RlCompleter = Completer - self.allow_kbdint = False self.nosigint = nosigint # Consider these characters as part of the command so when the users type @@ -918,6 +910,31 @@ def set_convenience_variable(self, frame, name, value): # Generic completion functions. Individual complete_foo methods can be # assigned below to one of these functions. + @property + def rlcompleter(self): + """Return the `Completer` class from `rlcompleter`, while avoiding the + side effects of changing the completer from `import rlcompleter`. + + This is a compromise between GH-138860 and GH-139289. If GH-139289 is + fixed, then we don't need this and we can just `import rlcompleter` in + `Pdb.__init__`. + """ + if not hasattr(self, "_rlcompleter"): + try: + import readline + except ImportError: + # readline is not available, just get the Completer + from rlcompleter import Completer + self._rlcompleter = Completer + else: + # importing rlcompleter could have side effect of changing + # the current completer, we need to restore it + prev_completer = readline.get_completer() + from rlcompleter import Completer + self._rlcompleter = Completer + readline.set_completer(prev_completer) + return self._rlcompleter + def completenames(self, text, line, begidx, endidx): # Overwrite completenames() of cmd so for the command completion, # if no current command matches, check for expressions as well @@ -996,7 +1013,7 @@ def completedefault(self, text, line, begidx, endidx): state = 0 matches = [] - completer = self.RlCompleter(self.curframe.f_globals | self.curframe.f_locals) + completer = self.rlcompleter(self.curframe.f_globals | self.curframe_locals) while (match := completer.complete(text, state)) is not None: matches.append(match) state += 1 diff --git a/Lib/test/test_pyclbr.py b/Lib/test/test_pyclbr.py index a65705aaf53abc..01f43ac1068df5 100644 --- a/Lib/test/test_pyclbr.py +++ b/Lib/test/test_pyclbr.py @@ -225,7 +225,7 @@ def test_others(self): cm( 'pdb', # pyclbr does not handle elegantly `typing` or properties - ignore=('Union', '_ModuleTarget', '_ScriptTarget', '_ZipTarget'), + ignore=('Union', '_ModuleTarget', '_ScriptTarget', '_ZipTarget', 'rlcompleter'), ) cm('pydoc', ignore=('input', 'output',)) # properties diff --git a/Misc/NEWS.d/next/Library/2025-09-24-14-17-34.gh-issue-139289.Vmk25k.rst b/Misc/NEWS.d/next/Library/2025-09-24-14-17-34.gh-issue-139289.Vmk25k.rst new file mode 100644 index 00000000000000..04162619cf218b --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-09-24-14-17-34.gh-issue-139289.Vmk25k.rst @@ -0,0 +1 @@ +Do a real lazy-import on :mod:`rlcompleter` in :mod:`pdb` and restore the existing completer after importing :mod:`rlcompleter`.