gh-130472: Integrate fancycompleter with the new repl, to get colored tab completions

Doc/using/cmdline.rst

@@ -1338,6 +1338,13 @@ conflict.
 
  .. versionadded:: 3.13
 
+.. envvar:: PYTHON_BASIC_COMPLETER
+
+ If this variable is set to any value, PyREPL will use :mod:`rlcompleter` to
+ implement tab completion, instead of the default one which uses colors.
+
+ .. versionadded:: 3.15
+
 .. envvar:: PYTHON_HISTORY
 
  This environment variable can be used to set the location of a

Lib/_colorize.py

@@ -15,7 +15,6 @@
 
 class ANSIColors:
  RESET = "\x1b[0m"
-
  BLACK = "\x1b[30m"
  BLUE = "\x1b[34m"
  CYAN = "\x1b[36m"
@@ -200,6 +199,30 @@ class Difflib(ThemeSection):
  reset: str = ANSIColors.RESET
 
 
+@dataclass(frozen=True, kw_only=True)
+class FancyCompleter(ThemeSection):
+ # functions and methods
+ function: str = ANSIColors.BOLD_BLUE
+ builtin_function_or_method: str = ANSIColors.BOLD_BLUE
+ method: str = ANSIColors.BOLD_CYAN
+ method_wrapper: str = ANSIColors.BOLD_CYAN
+ wrapper_descriptor: str = ANSIColors.BOLD_CYAN
+ method_descriptor: str = ANSIColors.BOLD_CYAN
+
+ # numbers
+ int: str = ANSIColors.BOLD_YELLOW
+ float: str = ANSIColors.BOLD_YELLOW
+ complex: str = ANSIColors.BOLD_YELLOW
+ bool: str = ANSIColors.BOLD_YELLOW
+
+ # others
+ type: str = ANSIColors.BOLD_MAGENTA
+ module: str = ANSIColors.CYAN
+ NoneType: str = ANSIColors.GREY
+ bytes: str = ANSIColors.BOLD_GREEN
+ str: str = ANSIColors.BOLD_GREEN
+
+
 @dataclass(frozen=True, kw_only=True)
 class LiveProfiler(ThemeSection):
  """Theme section for the live profiling TUI (Tachyon profiler).
@@ -354,6 +377,7 @@ class Theme:
  """
  argparse: Argparse = field(default_factory=Argparse)
  difflib: Difflib = field(default_factory=Difflib)
+ fancycompleter: FancyCompleter = field(default_factory=FancyCompleter)
  live_profiler: LiveProfiler = field(default_factory=LiveProfiler)
  syntax: Syntax = field(default_factory=Syntax)
  traceback: Traceback = field(default_factory=Traceback)
@@ -364,6 +388,7 @@ def copy_with(
  *,
  argparse: Argparse | None = None,
  difflib: Difflib | None = None,
+ fancycompleter: FancyCompleter | None = None,
  live_profiler: LiveProfiler | None = None,
  syntax: Syntax | None = None,
  traceback: Traceback | None = None,
@@ -377,6 +402,7 @@ def copy_with(
  return type(self)(
  argparse=argparse or self.argparse,
  difflib=difflib or self.difflib,
+ fancycompleter=fancycompleter or self.fancycompleter,
  live_profiler=live_profiler or self.live_profiler,
  syntax=syntax or self.syntax,
  traceback=traceback or self.traceback,
@@ -394,6 +420,7 @@ def no_colors(cls) -> Self:
  return cls(
  argparse=Argparse.no_colors(),
  difflib=Difflib.no_colors(),
+ fancycompleter=FancyCompleter.no_colors(),
  live_profiler=LiveProfiler.no_colors(),
  syntax=Syntax.no_colors(),
  traceback=Traceback.no_colors(),

Lib/_pyrepl/completing_reader.py

@@ -178,12 +178,14 @@ def do(self) -> None:
  if not completions:
  r.error("no matches")
  elif len(completions) == 1:
- if completions_unchangable and len(completions[0]) == len(stem):
+ completion = stripcolor(completions[0])
+ if completions_unchangable and len(completion) == len(stem):
  r.msg = "[ sole completion ]"
  r.dirty = True
- r.insert(completions[0][len(stem):])
+ r.insert(completion[len(stem):])
  else:
- p = prefix(completions, len(stem))
+ clean_completions = [stripcolor(word) for word in completions]
+ p = prefix(clean_completions, len(stem))
  if p:
  r.insert(p)
  if last_is_completer:
@@ -195,7 +197,7 @@ def do(self) -> None:
  r.dirty = True
  elif not r.cmpltn_menu_visible:
  r.cmpltn_message_visible = True
- if stem + p in completions:
+ if stem + p in clean_completions:
  r.msg = "[ complete but not unique ]"
  r.dirty = True
  else:
@@ -215,7 +217,7 @@ def do(self) -> None:
  r.cmpltn_reset()
  else:
  completions = [w for w in r.cmpltn_menu_choices
- if w.startswith(stem)]
+ if stripcolor(w).startswith(stem)]
  if completions:
  r.cmpltn_menu, r.cmpltn_menu_end = build_menu(
  r.console, completions, 0,

Lib/_pyrepl/fancycompleter.py

@@ -0,0 +1,210 @@
+# Copyright 2010-2025 Antonio Cuni
+# Daniel Hahler
+#
+# All Rights Reserved
+"""Colorful tab completion for Python prompt"""
+from _colorize import ANSIColors, get_colors, get_theme
+import rlcompleter
+import keyword
+import types
+
+class Completer(rlcompleter.Completer):
+ """
+ When doing something like a.b.<tab>, keep the full a.b.attr completion
+ stem so readline-style completion can keep refining the menu as you type.
+
+ Optionally, display the various completions in different colors
+ depending on the type.
+ """
+ def __init__(
+ self,
+ namespace=None,
+ *,
+ use_colors='auto',
+ consider_getitems=True,
+ ):
+ from _pyrepl import readline
+ rlcompleter.Completer.__init__(self, namespace)
+ if use_colors == 'auto':
+ # use colors only if we can
+ use_colors = get_colors().RED != ""
+ self.use_colors = use_colors
+ self.consider_getitems = consider_getitems
+
+ if self.use_colors:
+ # In GNU readline, this prevents escaping of ANSI control
+ # characters in completion results. pyrepl's parse_and_bind()
+ # is a no-op, but pyrepl handles ANSI sequences natively
+ # via real_len()/stripcolor().
+ readline.parse_and_bind('set dont-escape-ctrl-chars on')
+ self.theme = get_theme()
+ else:
+ self.theme = None
+
+ if self.consider_getitems:
+ delims = readline.get_completer_delims()
+ delims = delims.replace('[', '')
+ delims = delims.replace(']', '')
+ readline.set_completer_delims(delims)
+
+ def complete(self, text, state):
+ # if you press <tab> at the beginning of a line, insert an actual
+ # \t. Else, trigger completion.
+ if text == "":
+ return ('\t', None)[state]
+ else:
+ return rlcompleter.Completer.complete(self, text, state)
+
+ def _callable_postfix(self, val, word):
+ # disable automatic insertion of '(' for global callables
+ return word
+
+ def _callable_attr_postfix(self, val, word):
+ return rlcompleter.Completer._callable_postfix(self, val, word)
+
+ def global_matches(self, text):
+ names = rlcompleter.Completer.global_matches(self, text)
+ prefix = commonprefix(names)
+ if prefix and prefix != text:
+ return [prefix]
+
+ names.sort()
+ values = []
+ for name in names:
+ clean_name = name.rstrip(': ')
+ if keyword.iskeyword(clean_name) or keyword.issoftkeyword(clean_name):
+ values.append(None)
+ else:
+ try:
+ values.append(eval(name, self.namespace))
+ except Exception:
+ values.append(None)
+ if self.use_colors and names:
+ return self.colorize_matches(names, values)
+ return names
+
+ def attr_matches(self, text):
+ try:
+ expr, attr, names, values = self._attr_matches(text)
+ except ValueError:
+ return []
+
+ if not names:
+ return []
+
+ if len(names) == 1:
+ # No coloring: when returning a single completion, readline
+ # inserts it directly into the prompt, so ANSI codes would
+ # appear as literal characters.
+ return [self._callable_attr_postfix(values[0], f'{expr}.{names[0]}')]
+
+ prefix = commonprefix(names)
+ if prefix and prefix != attr:
+ return [f'{expr}.{prefix}'] # autocomplete prefix
+
+ names = [f'{expr}.{name}' for name in names]
+ if self.use_colors:
+ return self.colorize_matches(names, values)
+
+ if prefix:
+ names.append(' ')
+ return names
+
+ def _attr_matches(self, text):
+ expr, attr = text.rsplit('.', 1)
+ if '(' in expr or ')' in expr: # don't call functions
+ return expr, attr, [], []
+ try:
+ thisobject = eval(expr, self.namespace)
+ except Exception:
+ return expr, attr, [], []
+
+ # get the content of the object, except __builtins__
+ words = set(dir(thisobject)) - {'__builtins__'}
+
+ if hasattr(thisobject, '__class__'):
+ words.add('__class__')
+ words.update(rlcompleter.get_class_members(thisobject.__class__))
+ names = []
+ values = []
+ n = len(attr)
+ if attr == '':
+ noprefix = '_'
+ elif attr == '_':
+ noprefix = '__'
+ else:
+ noprefix = None
+
+ # sort the words now to make sure to return completions in
+ # alphabetical order. It's easier to do it now, else we would need to
+ # sort 'names' later but make sure that 'values' in kept in sync,
+ # which is annoying.
+ words = sorted(words)
+ while True:
+ for word in words:
+ if (
+ word[:n] == attr
+ and not (noprefix and word[:n+1] == noprefix)
+ ):
+ # Mirror rlcompleter's safeguards so completion does not
+ # call properties or reify lazy module attributes.
+ if isinstance(getattr(type(thisobject), word, None), property):
+ value = None
+ elif (
+ isinstance(thisobject, types.ModuleType)
+ and isinstance(
+ thisobject.__dict__.get(word),
+ types.LazyImportType,
+ )
+ ):
+ value = thisobject.__dict__.get(word)
+ else:
+ value = getattr(thisobject, word, None)
+
+ names.append(word)
+ values.append(value)
+ if names or not noprefix:
+ break
+ if noprefix == '_':
+ noprefix = '__'
+ else:
+ noprefix = None
+
+ return expr, attr, names, values
+
+ def colorize_matches(self, names, values):
+ matches = [self._color_for_obj(i, name, obj)
+ for i, (name, obj)
+ in enumerate(zip(names, values))]
+ # We add a space at the end to prevent the automatic completion of the
+ # common prefix, which is the ANSI escape sequence.
+ matches.append(' ')
+ return matches
+
+ def _color_for_obj(self, i, name, value):
+ t = type(value)
+ color = self._color_by_type(t)
+ # Encode the match index into a fake escape sequence that
+ # stripcolor() can still remove once i reaches four digits.
+ N = f"\x1b[{i // 100:03d};{i % 100:02d}m"
+ return f"{N}{color}{name}{ANSIColors.RESET}"
+
+ def _color_by_type(self, t):
+ typename = t.__name__
+ # this is needed e.g. to turn method-wrapper into method_wrapper,
+ # because if we want _colorize.FancyCompleter to be "dataclassable"
+ # our keys need to be valid identifiers.
+ typename = typename.replace('-', '_').replace('.', '_')
+ return getattr(self.theme.fancycompleter, typename, ANSIColors.RESET)
+
+
+def commonprefix(names):
+ """Return the common prefix of all 'names'"""
+ if not names:
+ return ''
+ s1 = min(names)
+ s2 = max(names)
+ for i, c in enumerate(s1):
+ if c != s2[i]:
+ return s1[:i]
+ return s1

Lib/_pyrepl/readline.py

@@ -40,6 +40,7 @@
 from .completing_reader import CompletingReader
 from .console import Console as ConsoleType
 from ._module_completer import ModuleCompleter, make_default_module_completer
+from .fancycompleter import Completer as FancyCompleter
 
 Console: type[ConsoleType]
 _error: tuple[type[Exception], ...] | type[Exception]
@@ -609,7 +610,12 @@ def _setup(namespace: Mapping[str, Any]) -> None:
  if not isinstance(namespace, dict):
  namespace = dict(namespace)
  _wrapper.config.module_completer = ModuleCompleter(namespace)
- _wrapper.config.readline_completer = RLCompleter(namespace).complete
+ use_basic_completer = (
+ not sys.flags.ignore_environment
+ and os.getenv("PYTHON_BASIC_COMPLETER")
+ )
+ completer_cls = RLCompleter if use_basic_completer else FancyCompleter
+ _wrapper.config.readline_completer = completer_cls(namespace).complete
 
  # this is not really what readline.c does. Better than nothing I guess
  import builtins