gh-111201: Support pyrepl on Windows (#119559)

Co-authored-by: Anthony Shaw <[email protected]>
Co-authored-by: Łukasz Langa <[email protected]>

Author: 3 people

Doc/whatsnew/3.13.rst

@@ -154,10 +154,10 @@ New Features
 A Better Interactive Interpreter
 --------------------------------
 
-On Unix-like systems like Linux or macOS, Python now uses a new
-:term:`interactive` shell. When the user starts the :term:`REPL` from an
-interactive terminal, and both :mod:`curses` and :mod:`readline` are
-available, the interactive shell now supports the following new features:
+On Unix-like systems like Linux or macOS as well as Windows, Python now
+uses a new :term:`interactive` shell. When the user starts the
+:term:`REPL` from an interactive terminal the interactive shell now
+supports the following new features:
 
 * Colorized prompts.
 * Multiline editing with history preservation.
@@ -174,10 +174,13 @@ available, the interactive shell now supports the following new features:
 If the new interactive shell is not desired, it can be disabled via
 the :envvar:`PYTHON_BASIC_REPL` environment variable.
 
+The new shell requires :mod:`curses` on Unix-like systems.
+
 For more on interactive mode, see :ref:`tut-interac`.
 
 (Contributed by Pablo Galindo Salgado, Łukasz Langa, and
-Lysandros Nikolaou in :gh:`111201` based on code from the PyPy project.)
+Lysandros Nikolaou in :gh:`111201` based on code from the PyPy project.
+Windows support contributed by Dino Viehland and Anthony Shaw.)
 
 .. _whatsnew313-improved-error-messages:
 

Lib/_pyrepl/__main__.py

@@ -1,7 +1,11 @@
 import os
 import sys
 
-CAN_USE_PYREPL = sys.platform != "win32"
+CAN_USE_PYREPL: bool
+if sys.platform != "win32":
+    CAN_USE_PYREPL = True
+else:
+    CAN_USE_PYREPL = sys.getwindowsversion().build >= 10586  # Windows 10 TH2
 
 
 def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):

Lib/_pyrepl/console.py

@@ -19,10 +19,18 @@
 
 from __future__ import annotations
 
+import sys
+
 from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
 
 
+TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import IO
+
+
 @dataclass
 class Event:
     evt: str
@@ -36,6 +44,25 @@ class Console(ABC):
     height: int = 25
     width: int = 80
 
+    def __init__(
+        self,
+        f_in: IO[bytes] | int = 0,
+        f_out: IO[bytes] | int = 1,
+        term: str = "",
+        encoding: str = "",
+    ):
+        self.encoding = encoding or sys.getdefaultencoding()
+
+        if isinstance(f_in, int):
+            self.input_fd = f_in
+        else:
+            self.input_fd = f_in.fileno()
+
+        if isinstance(f_out, int):
+            self.output_fd = f_out
+        else:
+            self.output_fd = f_out.fileno()
+
     @abstractmethod
     def refresh(self, screen: list[str], xy: tuple[int, int]) -> None: ...
 
@@ -108,5 +135,4 @@ def wait(self) -> None:
         ...
 
     @abstractmethod
-    def repaint(self) -> None:
-        ...
+    def repaint(self) -> None: ...

Lib/_pyrepl/reader.py

@@ -442,14 +442,13 @@ def get_arg(self, default: int = 1) -> int:
         """
         if self.arg is None:
             return default
-        else:
-            return self.arg
+        return self.arg
 
     def get_prompt(self, lineno: int, cursor_on_line: bool) -> str:
         """Return what should be in the left-hand margin for line
         'lineno'."""
         if self.arg is not None and cursor_on_line:
-            prompt = "(arg: %s) " % self.arg
+            prompt = f"(arg: {self.arg}) "
         elif self.paste_mode:
             prompt = "(paste) "
         elif "\n" in self.buffer:
@@ -515,12 +514,12 @@ def pos2xy(self) -> tuple[int, int]:
             offset = l - 1 if in_wrapped_line else l  # need to remove backslash
             if offset >= pos:
                 break
+
+            if p + sum(l2) >= self.console.width:
+                pos -= l - 1  # -1 cause backslash is not in buffer
             else:
-                if p + sum(l2) >= self.console.width:
-                    pos -= l - 1  # -1 cause backslash is not in buffer
-                else:
-                    pos -= l + 1  # +1 cause newline is in buffer
-                y += 1
+                pos -= l + 1  # +1 cause newline is in buffer
+            y += 1
         return p + sum(l2[:pos]), y
 
     def insert(self, text: str | list[str]) -> None:
@@ -582,7 +581,6 @@ def suspend(self) -> SimpleContextManager:
             for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode"):
                 setattr(self, arg, prev_state[arg])
             self.prepare()
-            pass
 
     def finish(self) -> None:
         """Called when a command signals that we're finished."""

Lib/_pyrepl/readline.py

@@ -38,7 +38,14 @@
 
 from . import commands, historical_reader
 from .completing_reader import CompletingReader
-from .unix_console import UnixConsole, _error
+from .console import Console as ConsoleType
+
+Console: type[ConsoleType]
+_error: tuple[type[Exception], ...] | type[Exception]
+try:
+    from .unix_console import UnixConsole as Console, _error
+except ImportError:
+    from .windows_console import WindowsConsole as Console, _error
 
 ENCODING = sys.getdefaultencoding() or "latin1"
 
@@ -328,7 +335,7 @@ def __post_init__(self) -> None:
 
     def get_reader(self) -> ReadlineAlikeReader:
         if self.reader is None:
-            console = UnixConsole(self.f_in, self.f_out, encoding=ENCODING)
+            console = Console(self.f_in, self.f_out, encoding=ENCODING)
             self.reader = ReadlineAlikeReader(console=console, config=self.config)
         return self.reader
 

Lib/_pyrepl/simple_interact.py

@@ -34,8 +34,12 @@
 from types import ModuleType
 
 from .readline import _get_reader, multiline_input
-from .unix_console import _error
 
+_error: tuple[type[Exception], ...] | type[Exception]
+try:
+    from .unix_console import _error
+except ModuleNotFoundError:
+    from .windows_console import _error
 
 def check() -> str:
     """Returns the error message if there is a problem initializing the state."""

Lib/_pyrepl/unix_console.py

@@ -143,18 +143,7 @@ def __init__(
         - term (str): Terminal name.
         - encoding (str): Encoding to use for I/O operations.
         """
-
-        self.encoding = encoding or sys.getdefaultencoding()
-
-        if isinstance(f_in, int):
-            self.input_fd = f_in
-        else:
-            self.input_fd = f_in.fileno()
-
-        if isinstance(f_out, int):
-            self.output_fd = f_out
-        else:
-            self.output_fd = f_out.fileno()
+        super().__init__(f_in, f_out, term, encoding)
 
         self.pollob = poll()
         self.pollob.register(self.input_fd, select.POLLIN)
@@ -592,14 +581,19 @@ def __write_changed_line(self, y, oldline, newline, px_coord):
         px_pos = 0
         j = 0
         for c in oldline:
-            if j >= px_coord: break
+            if j >= px_coord:
+                break
             j += wlen(c)
             px_pos += 1
 
         # reuse the oldline as much as possible, but stop as soon as we
         # encounter an ESCAPE, because it might be the start of an escape
         # sequene
-        while x_coord < minlen and oldline[x_pos] == newline[x_pos] and newline[x_pos] != "\x1b":
+        while (
+            x_coord < minlen
+            and oldline[x_pos] == newline[x_pos]
+            and newline[x_pos] != "\x1b"
+        ):
             x_coord += wlen(newline[x_pos])
             x_pos += 1
 
@@ -619,7 +613,11 @@ def __write_changed_line(self, y, oldline, newline, px_coord):
             self.__posxy = x_coord + character_width, y
 
         # if it's a single character change in the middle of the line
-        elif x_coord < minlen and oldline[x_pos + 1 :] == newline[x_pos + 1 :] and wlen(oldline[x_pos]) == wlen(newline[x_pos]):
+        elif (
+            x_coord < minlen
+            and oldline[x_pos + 1 :] == newline[x_pos + 1 :]
+            and wlen(oldline[x_pos]) == wlen(newline[x_pos])
+        ):
             character_width = wlen(newline[x_pos])
             self.__move(x_coord, y)
             self.__write(newline[x_pos])