Source code for userinterfaces.terminal_interface_base

"""Base for terminal user interfaces."""
# (C) Pywikibot team, 2003-2024
# Distributed under the terms of the MIT license.
from __future__ import annotations

import getpass
import logging
import re
import sys
import threading
from typing import Any

import pywikibot
from pywikibot import config
from pywikibot.backports import Iterable, Sequence, removeprefix
from pywikibot.bot_choice import (
from pywikibot.logging import INFO, INPUT, STDOUT, VERBOSE, WARNING
from import issue_deprecation_warning
from import RLock
from pywikibot.userinterfaces import transliteration
from pywikibot.userinterfaces._interface_base import ABUIC

transliterator = transliteration.Transliterator(config.console_encoding)

#: Colors supported by Pywikibot
colors = [

_color_pat = '((:?{0});?(:?{0})?)'.format('|'.join(colors + ['previous']))
old_colorTagR = re.compile(f'\03{{{_color_pat}}}')
new_colorTagR = re.compile(f'<<{_color_pat}>>')

[docs] class UI(ABUIC): """Base for terminal user interfaces. .. versionchanged:: 6.2: subclassed from :py:obj:`userinterfaces._interface_base.ABUIC` """ split_col_pat = re.compile(r'(\w+);?(\w+)?') def __init__(self) -> None: """ Initialize the UI. This caches the std-streams locally so any attempts to monkey-patch the streams later will not work. .. versionchanged:: 7.1 memorize original streams """ # for Windows GUI they can be None under some conditions self.stdin = sys.__stdin__ or sys.stdin self.stdout = sys.__stdout__ or sys.stdout self.stderr = sys.__stderr__ or sys.stderr self.argv = sys.argv self.encoding = config.console_encoding self.transliteration_target = config.transliteration_target self.cache = [] self.lock = RLock()
[docs] def init_handlers( self, root_logger, default_stream: str = 'stderr' ) -> None: """Initialize the handlers for user output. This method initializes handler(s) for output levels VERBOSE (if enabled by config.verbose_output), INFO, STDOUT, WARNING, ERROR, and CRITICAL. STDOUT writes its output to sys.stdout; all the others write theirs to sys.stderr. """ if default_stream == 'stdout': default_stream = self.stdout elif default_stream == 'stderr': default_stream = self.stderr # default handler for display to terminal default_handler = TerminalHandler(self, stream=default_stream) if config.verbose_output: default_handler.setLevel(VERBOSE) else: default_handler.setLevel(INFO) # this handler ignores levels above INPUT default_handler.addFilter(MaxLevelFilter(INPUT)) default_handler.setFormatter( logging.Formatter(fmt='%(message)s%(newline)s')) root_logger.addHandler(default_handler) # handler for level STDOUT output_handler = TerminalHandler(self, stream=self.stdout) output_handler.setLevel(STDOUT) output_handler.addFilter(MaxLevelFilter(STDOUT)) output_handler.setFormatter( logging.Formatter(fmt='%(message)s%(newline)s')) root_logger.addHandler(output_handler) # handler for levels WARNING and higher warning_handler = TerminalHandler(self, stream=self.stderr) warning_handler.setLevel(WARNING) warning_handler.setFormatter( logging.Formatter(fmt='%(levelname)s: %(message)s%(newline)s')) root_logger.addHandler(warning_handler) warnings_logger = logging.getLogger('py.warnings') warnings_logger.addHandler(warning_handler)
[docs] def encounter_color(self, color, target_stream): """Abstract method to handle the next color encountered.""" raise NotImplementedError('The {} class does not support ' 'colors.'.format(self.__class__.__name__))
[docs] @classmethod def divide_color(cls, color): """ Split color label in a tuple. Received color is a string like 'fg_color;bg_color' or 'fg_color'. Returned values are (fg_color, bg_color) or (fg_color, None). """ return
def _write(self, text: str, target_stream) -> None: """Write the text to the target stream. sys.stderr and sys.stdout are frozen upon initialization to original streams (which are stored in the sys module as `sys.__stderr__` and `sys.__stdout__`). This works fine except when using `redirect_stderr` or `redirect_stdout` context managers, where values of global `sys.stderr` and `sys.stdout` are temporarily changed to a redirecting `StringIO` stream, in which case writing to the frozen streams (which are still set to `sys.__stderr__` / `sys.__stdout__`) will not write to the redirecting stream as expected. So, we check the target stream against the frozen streams, and then write to the (potentially redirected) `sys.stderr` or `sys.stdout` stream. .. versionchanged:: 7.1 instead of writing to `target_stream`, dispatch to `sys.stderr` or `sys.stdout`. """ if target_stream == self.stderr: sys.stderr.write(text) elif target_stream == self.stdout: sys.stdout.write(text) else: # pragma: no cover try: out, err =, except AttributeError: out, err = self.stdout, self.stderr raise OSError( 'Target stream {} is neither stdin ({}) nor stderr ({})' .format(, out, err))
[docs] def support_color(self, target_stream) -> bool: """Return whether the target stream does support colors.""" return False
def _print(self, text, target_stream) -> None: """Write the text to the target stream handling the colors.""" colorized = (config.colorized_output and self.support_color(target_stream)) colored_line = False # Color tags might be cascaded, e.g. because of transliteration. # Therefore we need this stack. color_stack = ['default'] old_parts = old_colorTagR.split(text) new_parts = new_colorTagR.split(text) if min(len(old_parts), len(new_parts)) > 1: raise ValueError('Old color format must not be mixed with new ' 'color format. Found:\n' + text.replace('\03', '\\03')) if len(old_parts) > 1: issue_deprecation_warning( 'old color format variant like \03{color}', 'new color format like <<color>>', since='7.3.0') text_parts = old_parts else: text_parts = new_parts text_parts.append('default') # match.split() includes every regex group; for each matched color # fg_col:b_col, fg_col and bg_col are added to the resulting list. len_text_parts = len(text_parts[::4]) for index, (text, next_color) in enumerate(zip(text_parts[::4], text_parts[1::4])): current_color = color_stack[-1] if next_color == 'previous': if len(color_stack) > 1: # keep the last element in the stack color_stack.pop() next_color = color_stack[-1] else: color_stack.append(next_color) if current_color != next_color: colored_line = True if colored_line and not colorized: if '\n' in text: # Normal end of line text = text.replace('\n', ' ***\n', 1) colored_line = False elif index == len_text_parts - 1: # Or end of text text += ' ***' colored_line = False # print the text up to the tag. self._write(text, target_stream) if current_color != next_color and colorized: # set the new color, but only if they change # flush first to enable color change on Windows (T283808) target_stream.flush() self.encounter_color(color_stack[-1], target_stream) # finally flush stream to show the text, required for Windows (T303373) target_stream.flush()
[docs] def output(self, text, targetStream=None) -> None: """Forward text to cache and flush if output is not locked. All input methods locks the output to a stream but collect them in cache. They will be printed with next unlocked output call or at termination time. .. versionchanged:: 7.0 Forward text to cache and flush if output is not locked. """ self.cache_output(text, targetStream=targetStream) if not self.lock.locked(): self.flush()
[docs] def flush(self) -> None: """Output cached text. .. versionadded:: 7.0 """ with self.lock: for args, kwargs in self.cache: self.stream_output(*args, **kwargs) self.cache.clear()
[docs] def cache_output(self, *args, **kwargs) -> None: """Put text to cache. .. versionadded:: 7.0 """ with self.lock: self.cache.append((args, kwargs))
[docs] def stream_output(self, text, targetStream=None) -> None: """Output text to a stream. If a character can't be displayed in the encoding used by the user's terminal, it will be replaced with a question mark or by a transliteration. .. versionadded:: 7.0 ``UI.output()`` was renamed to ``UI.stream_output()`` """ if config.transliterate: # Encode our unicode string in the encoding used by the user's # console, and decode it back to unicode. Then we can see which # characters can't be represented in the console encoding. # We need to take min(console_encoding, transliteration_target) # the first is what the terminal is capable of # the second is how unicode-y the user would like the output codecedText = text.encode(self.encoding, 'replace').decode(self.encoding) if self.transliteration_target: codecedText = codecedText.encode( self.transliteration_target, 'replace').decode(self.transliteration_target) transliteratedText = '' # Note: A transliteration replacement might be longer than the # original character, e.g. ч is transliterated to ch. prev = '-' for i, char in enumerate(codecedText): # work on characters that couldn't be encoded, but not on # original question marks. if char == '?' and text[i] != '?': try: transliterated = transliterator.transliterate( text[i], default='?', prev=prev, succ=text[i + 1]) except IndexError: transliterated = transliterator.transliterate( text[i], default='?', prev=prev, succ=' ') # transliteration was successful. The replacement # could consist of multiple letters. # mark the transliterated letters in yellow. transliteratedText = ''.join((transliteratedText, '<<lightyellow>>', transliterated, '<<previous>>')) # memorize if we replaced a single letter by multiple # letters. if transliterated: prev = transliterated[-1] else: # no need to try to transliterate. transliteratedText += char prev = char text = transliteratedText if not targetStream: targetStream = self.stderr self._print(text, targetStream)
def _raw_input(self): # May be overridden by subclass return input()
[docs] def input(self, question: str, password: bool = False, default: str | None = '', force: bool = False) -> str: """ Ask the user a question and return the answer. Works like raw_input(), but returns a unicode string instead of ASCII. Unlike raw_input, this function automatically adds a colon and space after the question if they are not already present. Also recognises a trailing question mark. :param question: The question, without trailing whitespace. :param password: if True, hides the user's input (for password entry). :param default: The default answer if none was entered. None to require an answer. :param force: Automatically use the default """ assert not password or not default question = question.strip() end_marker = question[-1] if end_marker in (':', '?'): question = question[:-1] else: end_marker = ':' if default: question += f' (default: {default})' question += end_marker # lock stream output with self.lock: if force: self.stream_output(question + '\n') return default # sound the terminal bell to notify the user if config.ring_bell: sys.stdout.write('\07') # TODO: make sure this is logged as well while True: self.stream_output(question + ' ') text = self._input_reraise_cntl_c(password) if text is None: continue if text: return text if default is not None: return default
def _input_reraise_cntl_c(self, password): """Input and decode, and re-raise Control-C.""" try: if password: # Python 3 requires that stderr gets flushed, otherwise is the # message only visible after the query. self.stderr.flush() text = getpass.getpass('') else: text = self._raw_input() except KeyboardInterrupt: raise QuitKeyboardInterrupt() except UnicodeDecodeError: return None # wrong terminal encoding, T258143 return text
[docs] def input_choice( self, question: str, options: Iterable[tuple[str, str] | Option] | Option, default: str | None = None, return_shortcut: bool = True, automatic_quit: bool = True, force: bool = False, ) -> Any: """Ask the user and returns a value from the options. Depending on the options setting *return_shortcut* to False may not be sensible when the option supports multiple values as it'll return an ambiguous index. .. versionchanged:: 9.0 Raise ValueError if no *default* value is given with *force*; raise ValueError if *force* is True and *default* value is invalid; raise TypeError if *default* value is neither str nor None. :param question: The question, without trailing whitespace. :param options: Iterable of all available options. Each entry contains the full length answer and a shortcut of only one character. Alternatively they may be Option (or subclass) instances or ChoiceException instances which have a full option and shortcut and will be raised if selected. :param default: The default answer if no was entered. None to require an answer. :param return_shortcut: Whether the shortcut or the index in the option should be returned. :param automatic_quit: Adds the option 'Quit' ('q') if True and throws a :py:obj:`QuitKeyboardInterrupt` if selected. :param force: Automatically use the default :return: If return_shortcut the shortcut of options or the value of default (if it's not None). Otherwise the index of the answer in options. If default is not a shortcut, it'll return -1. :raises ValueError: invalid or no *default* value is given with *force* or no or an invalid option is given. :raises TypeError: *default* value is neither None nor str """ def output_option(option, before_question) -> None: """Print an OutputOption before or after question.""" if isinstance(option, OutputOption) \ and option.before_question is before_question: self.stream_output(option.out + '\n') if force and not default: raise ValueError('With no default option it cannot be forced') if isinstance(options, Option): options = [options] else: # make a copy options = list(options) if not options: raise ValueError('No options are given.') if automatic_quit: options.append(QuitKeyboardInterrupt()) if isinstance(default, str): default = default.lower() elif default is not None: raise TypeError(f'Invalid type {type(default).__name__!r} for ' f"parameter 'default' ({default}); str expected") for i, option in enumerate(options): if not isinstance(option, Option): if len(option) != 2: raise ValueError('Option #{} does not consist of an ' 'option and shortcut.'.format(i)) options[i] = StandardOption(*option) # TODO: Test for uniquity handled = False # lock stream output with self.lock: while not handled: for option in options: output_option(option, before_question=True) output = Option.formatted(question, options, default) if force: self.stream_output(output + '\n') answer = default else: answer = self.input(output) or default # something entered or default is defined if answer: for index, option in enumerate(options): if option.handled(answer): answer = option.result(answer) output_option(option, before_question=False) handled = option.stop break else: if force: raise ValueError( f'{default!r} is not a valid Option for ' f'{removeprefix(output, question).lstrip()}') if isinstance(answer, ChoiceException): raise answer if not return_shortcut: return index return answer
[docs] def input_list_choice(self, question: str, answers: Sequence[Any], default: int | str | None = None, force: bool = False) -> Any: """Ask the user to select one entry from a list of entries. :param question: The question, without trailing whitespace. :param answers: A sequence of options to be choosen. :param default: The default answer if no was entered. None to require an answer. :param force: Automatically use the default. :return: Return a single Sequence entry. """ # lock stream output with self.lock: if not force: line_template = f'{{0: >{len(str(len(answers)))}}}: {{1}}\n' for i, entry in enumerate(answers, start=1): self.stream_output(line_template.format(i, entry)) while True: choice = self.input(question, default=default, force=force) try: choice = int(choice) - 1 except (TypeError, ValueError): if choice in answers: return choice choice = -1 # User typed choice number if 0 <= choice < len(answers): return answers[choice] if force: raise ValueError( f'Invalid value "{default}" for default during force.') self.stream_output('Error: Invalid response\n')
[docs] @staticmethod def editText(text: str, jumpIndex: int | None = None, highlight: str | None = None) -> str | None: """Return the text as edited by the user. Uses a Tkinter edit box because we don't have a console editor :param text: the text to be edited :param jumpIndex: position at which to put the caret :param highlight: each occurrence of this substring will be highlighted :return: the modified text, or None if the user didn't save the text file in his text editor """ try: from pywikibot.userinterfaces import gui except ImportError as e: pywikibot.warning(f'Could not load GUI modules: {e}') return text editor = gui.EditBoxWindow() return editor.edit(text, jumpIndex=jumpIndex, highlight=highlight)
[docs] class TerminalHandler(logging.StreamHandler): """A handler class that writes logging records to a terminal. This class does not close the stream, as sys.stdout or sys.stderr may be (and usually will be) used. Slightly modified version of the StreamHandler class that ships with logging module, plus code for colorization of output. """ # create a class-level lock that can be shared by all instances sharedlock = threading.RLock() def __init__(self, UI, stream=None) -> None: """Initialize the handler. If stream is not specified, sys.stderr is used. """ super().__init__(stream=stream) self.UI = UI
[docs] def createLock(self) -> None: """Acquire a thread lock for serializing access to the underlying I/O. Replace Handler's instance-specific lock with the shared class lock to ensure that only one instance of this handler can write to the console at a time. """ self.lock = TerminalHandler.sharedlock
[docs] def emit(self, record) -> None: """Emit the record formatted to the output.""" self.flush() if == 'py.warnings': # Each warning appears twice # the second time it has a 'message' if 'message' in record.__dict__: return record.__dict__.setdefault('newline', '\n') msg = self.format(record) self.UI.output(msg,
[docs] class MaxLevelFilter(): """Filter that only passes records at or below a specific level. .. note:: setting handler level only passes records at or *above* a specified level, so this provides the opposite functionality. """ def __init__(self, level=None) -> None: """Initializer.""" self.level = level
[docs] def filter(self, record): """Return true if the level is below or equal to the set level.""" if self.level: return record.levelno <= self.level return True