""" This is a python implementation of wcwidth() and wcswidth(). https://github.com/jquast/wcwidth from Markus Kuhn's C code, retrieved from: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c This is an implementation of wcwidth() and wcswidth() (defined in IEEE Std 1002.1-2001) for Unicode. http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html In fixed-width output devices, Latin characters all occupy a single "cell" position of equal width, whereas ideographic CJK characters occupy two such cells. Interoperability between terminal-line applications and (teletype-style) character terminals using the UTF-8 encoding requires agreement on which character should advance the cursor by how many cell positions. No established formal standards exist at present on which Unicode character shall occupy how many cell positions on character terminals. These routines are a first attempt of defining such behavior based on simple rules applied to data provided by the Unicode Consortium. For some graphical characters, the Unicode standard explicitly defines a character-cell width via the definition of the East Asian FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes. In all these cases, there is no ambiguity about which width a terminal shall use. For characters in the East Asian Ambiguous (A) class, the width choice depends purely on a preference of backward compatibility with either historic CJK or Western practice. Choosing single-width for these characters is easy to justify as the appropriate long-term solution, as the CJK practice of displaying these characters as double-width comes from historic implementation simplicity (8-bit encoded characters were displayed single-width and 16-bit ones double-width, even for Greek, Cyrillic, etc.) and not any typographic considerations. Much less clear is the choice of width for the Not East Asian (Neutral) class. Existing practice does not dictate a width for any of these characters. It would nevertheless make sense typographically to allocate two character cells to characters such as for instance EM SPACE or VOLUME INTEGRAL, which cannot be represented adequately with a single-width glyph. The following routines at present merely assign a single-cell width to all neutral characters, in the interest of simplicity. This is not entirely satisfactory and should be reconsidered before establishing a formal standard in this area. At the moment, the decision which Not East Asian (Neutral) characters should be represented by double-width glyphs cannot yet be answered by applying a simple rule from the Unicode database content. Setting up a proper standard for the behavior of UTF-8 character terminals will require a careful analysis not only of each Unicode character, but also of each presentation form, something the author of these routines has avoided to do so far. http://www.unicode.org/unicode/reports/tr11/ Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c """ from __future__ import annotations # std imports from functools import lru_cache from typing import TYPE_CHECKING # local from .bisearch import bisearch as _bisearch from .grapheme import iter_graphemes from .table_mc import CATEGORY_MC from .sgr_state import (_SGR_PATTERN, _SGR_STATE_DEFAULT, _sgr_state_update, _sgr_state_is_active, _sgr_state_to_sequence) from .table_vs16 import VS16_NARROW_TO_WIDE from .table_wide import WIDE_EASTASIAN from .table_zero import ZERO_WIDTH from .control_codes import ILLEGAL_CTRL, VERTICAL_CTRL, HORIZONTAL_CTRL, ZERO_WIDTH_CTRL from .table_grapheme import ISC_CONSONANT, EXTENDED_PICTOGRAPHIC, GRAPHEME_REGIONAL_INDICATOR from .table_ambiguous import AMBIGUOUS_EASTASIAN from .escape_sequences import (ZERO_WIDTH_PATTERN, CURSOR_LEFT_SEQUENCE, CURSOR_RIGHT_SEQUENCE, INDETERMINATE_EFFECT_SEQUENCE) from .unicode_versions import list_versions if TYPE_CHECKING: # pragma: no cover # std imports from collections.abc import Iterator from typing import Literal # Pre-compute table references for the latest (and only) Unicode version. _LATEST_VERSION = list_versions()[-1] _ZERO_WIDTH_TABLE = ZERO_WIDTH[_LATEST_VERSION] _WIDE_EASTASIAN_TABLE = WIDE_EASTASIAN[_LATEST_VERSION] _AMBIGUOUS_TABLE = AMBIGUOUS_EASTASIAN[next(iter(AMBIGUOUS_EASTASIAN))] _CATEGORY_MC_TABLE = CATEGORY_MC[_LATEST_VERSION] _REGIONAL_INDICATOR_SET = frozenset( range(GRAPHEME_REGIONAL_INDICATOR[0][0], GRAPHEME_REGIONAL_INDICATOR[0][1] + 1) ) _EMOJI_ZWJ_SET = frozenset( cp for lo, hi in EXTENDED_PICTOGRAPHIC for cp in range(lo, hi + 1) ) | _REGIONAL_INDICATOR_SET _FITZPATRICK_RANGE = (0x1F3FB, 0x1F3FF) # Indic_Syllabic_Category=Virama codepoints, from IndicSyllabicCategory.txt. # These are structurally tied to their scripts and not expected to change. # https://www.unicode.org/Public/UCD/latest/ucd/IndicSyllabicCategory.txt _ISC_VIRAMA_SET = frozenset(( 0x094D, # DEVANAGARI SIGN VIRAMA 0x09CD, # BENGALI SIGN VIRAMA 0x0A4D, # GURMUKHI SIGN VIRAMA 0x0ACD, # GUJARATI SIGN VIRAMA 0x0B4D, # ORIYA SIGN VIRAMA 0x0BCD, # TAMIL SIGN VIRAMA 0x0C4D, # TELUGU SIGN VIRAMA 0x0CCD, # KANNADA SIGN VIRAMA 0x0D4D, # MALAYALAM SIGN VIRAMA 0x0DCA, # SINHALA SIGN AL-LAKUNA 0x1B44, # BALINESE ADEG ADEG 0xA806, # SYLOTI NAGRI SIGN HASANTA 0xA8C4, # SAURASHTRA SIGN VIRAMA 0xA9C0, # JAVANESE PANGKON 0x11046, # BRAHMI VIRAMA 0x110B9, # KAITHI SIGN VIRAMA 0x111C0, # SHARADA SIGN VIRAMA 0x11235, # KHOJKI SIGN VIRAMA 0x1134D, # GRANTHA SIGN VIRAMA 0x11442, # NEWA SIGN VIRAMA 0x114C2, # TIRHUTA SIGN VIRAMA 0x115BF, # SIDDHAM SIGN VIRAMA 0x1163F, # MODI SIGN VIRAMA 0x116B6, # TAKRI SIGN VIRAMA 0x11839, # DOGRA SIGN VIRAMA 0x119E0, # NANDINAGARI SIGN VIRAMA 0x11C3F, # BHAIKSUKI SIGN VIRAMA )) _ISC_CONSONANT_TABLE = ISC_CONSONANT # In 'parse' mode, strings longer than this are checked for cursor-movement # controls (BS, TAB, CR, cursor sequences); when absent, mode downgrades to # 'ignore' to skip character-by-character parsing. The detection scan cost is # negligible for long strings but wasted on short ones like labels or headings. _WIDTH_FAST_PATH_MIN_LEN = 20 # Translation table to strip C0/C1 control characters for fast 'ignore' mode. _CONTROL_CHAR_TABLE = str.maketrans('', '', ( ''.join(chr(c) for c in range(0x00, 0x20)) + # C0: NUL through US (including tab) '\x7f' + # DEL ''.join(chr(c) for c in range(0x80, 0xa0)) # C1: U+0080-U+009F )) # Unlike wcwidth.__all__, wcwidth.wcwidth.__all__ is NOT for the purpose of defining a public API, # or what we prefer to be imported with statement, "from wcwidth.wcwidth import *". Explicitly # re-export imports here for no other reason than to satisfy the type checkers (mypy). Yak shavings. __all__ = ( 'ZERO_WIDTH', 'WIDE_EASTASIAN', 'AMBIGUOUS_EASTASIAN', 'VS16_NARROW_TO_WIDE', 'list_versions', 'wcwidth', 'wcswidth', 'width', 'iter_sequences', 'ljust', 'rjust', 'center', 'clip', 'strip_sequences', '_wcmatch_version', '_wcversion_value', ) # maxsize=1024: western scripts need ~64 unique codepoints per session, but # CJK sessions may use ~2000 of ~3500 common hanzi/kanji. 1024 accommodates # heavy CJK use. Performance floor at 32; bisearch is ~100ns per miss. @lru_cache(maxsize=1024) def wcwidth(wc: str, unicode_version: str = 'auto', ambiguous_width: int = 1) -> int: # pylint: disable=unused-argument r""" Given one Unicode codepoint, return its printable length on a terminal. :param wc: A single Unicode character. :param unicode_version: Ignored. Retained for backwards compatibility. .. deprecated:: 0.3.0 Only the latest Unicode version is now shipped. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts where ambiguous characters display as double-width. See :ref:`ambiguous_width` for details. :returns: The width, in cells, necessary to display the character of Unicode string character, ``wc``. Returns 0 if the ``wc`` argument has no printable effect on a terminal (such as NUL '\0'), -1 if ``wc`` is not printable, or has an indeterminate effect on the terminal, such as a control character. Otherwise, the number of column positions the character occupies on a graphic terminal (1 or 2) is returned. See :ref:`Specification` for details of cell measurement. """ ucs = ord(wc) if wc else 0 # small optimization: early return of 1 for printable ASCII, this provides # approximately 40% performance improvement for mostly-ascii documents, with # less than 1% impact to others. if 32 <= ucs < 0x7f: return 1 # C0/C1 control characters are -1 for compatibility with POSIX-like calls if ucs and ucs < 32 or 0x07F <= ucs < 0x0A0: return -1 # Zero width if _bisearch(ucs, _ZERO_WIDTH_TABLE): return 0 # Wide (F/W categories) if _bisearch(ucs, _WIDE_EASTASIAN_TABLE): return 2 # Ambiguous width (A category) - only when ambiguous_width=2 if ambiguous_width == 2 and _bisearch(ucs, _AMBIGUOUS_TABLE): return 2 return 1 def wcswidth( pwcs: str, n: int | None = None, unicode_version: str = 'auto', ambiguous_width: int = 1, ) -> int: """ Given a unicode string, return its printable length on a terminal. :param pwcs: Measure width of given unicode string. :param n: When ``n`` is None (default), return the length of the entire string, otherwise only the first ``n`` characters are measured. Better to use string slicing capability, ``wcswidth(pwcs[:n])``, instead, for performance. This argument is a holdover from the POSIX function for matching signatures. Be careful that ``n`` is at grapheme boundaries. :param unicode_version: Ignored. Retained for backwards compatibility. .. deprecated:: 0.3.0 Only the latest Unicode version is now shipped. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :returns: The width, in cells, needed to display the first ``n`` characters of the unicode string ``pwcs``. Returns ``-1`` for C0 and C1 control characters! See :ref:`Specification` for details of cell measurement. """ # pylint: disable=unused-argument,too-many-locals,too-many-statements # pylint: disable=too-complex,too-many-branches # This function intentionally kept long without delegating functions to reduce function calls in # "hot path", the overhead per-character adds up. # Fast path: pure ASCII printable strings are always width == length if n is None and pwcs.isascii() and pwcs.isprintable(): return len(pwcs) # Select wcwidth call pattern for best lru_cache performance: # - ambiguous_width=1 (default): single-arg calls share cache with direct wcwidth() calls # - ambiguous_width=2: full positional args needed (results differ, separate cache is correct) _wcwidth = wcwidth if ambiguous_width == 1 else lambda c: wcwidth(c, 'auto', ambiguous_width) end = len(pwcs) if n is None else n total_width = 0 idx = 0 last_measured_idx = -2 # Track index of last measured char for VS16 last_measured_ucs = -1 # Codepoint of last measured char (for deferred emoji check) last_was_virama = False # Virama conjunct formation state conjunct_pending = False # Deferred +1 for bare conjuncts (no trailing Mc) while idx < end: char = pwcs[idx] ucs = ord(char) if ucs == 0x200D: if last_was_virama: # ZWJ after virama requests explicit half-form rendering but # does not change cell count — consume ZWJ only, let the next # consonant be handled by the virama conjunct rule. idx += 1 elif idx + 1 < end: # Emoji ZWJ: skip next character unconditionally. idx += 2 last_was_virama = False else: idx += 1 last_was_virama = False continue if ucs == 0xFE0F and last_measured_idx >= 0: # VS16 following a measured character: add 1 if that character is # known to be converted from narrow to wide by VS16. total_width += _bisearch(ord(pwcs[last_measured_idx]), VS16_NARROW_TO_WIDE["9.0.0"]) last_measured_idx = -2 # Prevent double application # VS16 preserves emoji context: last_measured_ucs stays as the base idx += 1 continue # Regional Indicator & Fitzpatrick: both above BMP (U+1F1E6+) if ucs > 0xFFFF: if ucs in _REGIONAL_INDICATOR_SET: # Lazy RI pairing: count preceding consecutive RIs only when the last one is # received, because RI's are received so rarely its better than per-loop tracking of # 'last char was an RI'. ri_before = 0 j = idx - 1 while j >= 0 and ord(pwcs[j]) in _REGIONAL_INDICATOR_SET: ri_before += 1 j -= 1 if ri_before % 2 == 1: # Second RI in pair: contributes 0 (pair = one 2-cell flag) using an even-or-odd # check to determine, 'CAUS' would be two flags, but 'CAU' would be 1 flag # and wide 'U'. idx += 1 last_measured_ucs = ucs continue # First or unpaired RI: measured normally (width 2 from table) # Fitzpatrick modifier: zero-width when following emoji base elif (_FITZPATRICK_RANGE[0] <= ucs <= _FITZPATRICK_RANGE[1] and last_measured_ucs in _EMOJI_ZWJ_SET): idx += 1 continue # Virama conjunct formation: consonant following virama contributes 0 width. # See https://www.unicode.org/reports/tr44/#Indic_Syllabic_Category if last_was_virama and _bisearch(ucs, _ISC_CONSONANT_TABLE): last_measured_idx = idx last_measured_ucs = ucs last_was_virama = False conjunct_pending = True idx += 1 continue wcw = _wcwidth(char) if wcw < 0: # early return -1 on C0 and C1 control characters return wcw if wcw > 0: if conjunct_pending: total_width += 1 conjunct_pending = False last_measured_idx = idx last_measured_ucs = ucs last_was_virama = False elif last_measured_idx >= 0 and _bisearch(ucs, _CATEGORY_MC_TABLE): # Spacing Combining Mark (Mc) following a base character adds 1 wcw = 1 last_measured_idx = -2 last_was_virama = False conjunct_pending = False else: last_was_virama = ucs in _ISC_VIRAMA_SET total_width += wcw idx += 1 if conjunct_pending: total_width += 1 return total_width # NOTE: _wcversion_value and _wcmatch_version are no longer used internally # by wcwidth since version 0.5.0 (only the latest Unicode version is shipped). # # They are retained for API compatibility with external tools like ucs-detect # that may use these private functions. @lru_cache(maxsize=128) def _wcversion_value(ver_string: str) -> tuple[int, ...]: # pragma: no cover """ Integer-mapped value of given dotted version string. .. deprecated:: 0.3.0 This function is no longer used internally by wcwidth but is retained for API compatibility with external tools. :param ver_string: Unicode version string, of form ``n.n.n``. :returns: tuple of digit tuples, ``tuple(int, [...])``. """ retval = tuple(map(int, (ver_string.split('.')))) return retval @lru_cache(maxsize=8) def _wcmatch_version(given_version: str) -> str: # pylint: disable=unused-argument """ Return the supported Unicode version level. .. deprecated:: 0.3.0 This function now always returns the latest version. This function is no longer used internally by wcwidth but is retained for API compatibility with external tools. :param given_version: Ignored. Any value is accepted for compatibility. :returns: The latest unicode version string. """ return _LATEST_VERSION def iter_sequences(text: str) -> Iterator[tuple[str, bool]]: r""" Iterate through text, yielding segments with sequence identification. This generator yields tuples of ``(segment, is_sequence)`` for each part of the input text, where ``is_sequence`` is ``True`` if the segment is a recognized terminal escape sequence. :param text: String to iterate through. :returns: Iterator of (segment, is_sequence) tuples. .. versionadded:: 0.3.0 Example:: >>> list(iter_sequences('hello')) [('hello', False)] >>> list(iter_sequences('\x1b[31mred')) [('\x1b[31m', True), ('red', False)] >>> list(iter_sequences('\x1b[1m\x1b[31m')) [('\x1b[1m', True), ('\x1b[31m', True)] """ idx = 0 text_len = len(text) segment_start = 0 while idx < text_len: char = text[idx] if char == '\x1b': # Yield any accumulated non-sequence text if idx > segment_start: yield (text[segment_start:idx], False) # Try to match an escape sequence match = ZERO_WIDTH_PATTERN.match(text, idx) if match: yield (match.group(), True) idx = match.end() else: # Lone ESC or unrecognized - yield as sequence anyway yield (char, True) idx += 1 segment_start = idx else: idx += 1 # Yield any remaining text if segment_start < text_len: yield (text[segment_start:], False) def _width_ignored_codes(text: str, ambiguous_width: int = 1) -> int: """ Fast path for width() with control_codes='ignore'. Strips escape sequences and control characters, then measures remaining text. """ return wcswidth( strip_sequences(text).translate(_CONTROL_CHAR_TABLE), ambiguous_width=ambiguous_width ) def width( text: str, *, control_codes: Literal['parse', 'strict', 'ignore'] = 'parse', tabsize: int = 8, ambiguous_width: int = 1, ) -> int: r""" Return printable width of text containing many kinds of control codes and sequences. Unlike :func:`wcswidth`, this function handles most control characters and many popular terminal output sequences. Never returns -1. :param text: String to measure. :param control_codes: How to handle control characters and sequences: - ``'parse'`` (default): Track horizontal cursor movement from BS ``\b``, CR ``\r``, TAB ``\t``, and cursor left and right movement sequences. Vertical movement (LF, VT, FF) and indeterminate sequences are zero-width. Never raises. - ``'strict'``: Like parse, but raises :exc:`ValueError` on control characters with indeterminate results of the screen or cursor, like clear or vertical movement. Generally, these should be handled with a virtual terminal emulator (like 'pyte'). - ``'ignore'``: All C0 and C1 control characters and escape sequences are measured as width 0. This is the fastest measurement for text already filtered or known not to contain any kinds of control codes or sequences. TAB ``\t`` is zero-width; for tab expansion, pre-process: ``text.replace('\t', ' ' * 8)``. :param tabsize: Tab stop width for ``'parse'`` and ``'strict'`` modes. Default is 8. Must be positive. Has no effect when ``control_codes='ignore'``. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :returns: Maximum cursor position reached, "extent", accounting for cursor movement sequences present in ``text`` according to given parameters. This represents the rightmost column the cursor reaches. Always a non-negative integer. :raises ValueError: If ``control_codes='strict'`` and control characters with indeterminate effects, such as vertical movement or clear sequences are encountered, or on unexpected C0 or C1 control code. Also raised when ``control_codes`` is not one of the valid values. .. versionadded:: 0.3.0 Examples:: >>> width('hello') 5 >>> width('コンニチハ') 10 >>> width('\x1b[31mred\x1b[0m') 3 >>> width('\x1b[31mred\x1b[0m', control_codes='ignore') # same result (ignored) 3 >>> width('123\b4') # backspace overwrites previous cell (outputs '124') 3 >>> width('abc\t') # tab caused cursor to move to column 8 8 >>> width('1\x1b[10C') # '1' + cursor right 10, cursor ends on column 11 11 >>> width('1\x1b[10C', control_codes='ignore') # faster but wrong in this case 1 """ # pylint: disable=too-complex,too-many-branches,too-many-statements,too-many-locals # This could be broken into sub-functions (#1, #3, and 6 especially), but for reduced overhead # considering this function is a likely "hot path", they are inlined, breaking many of our # complexity rules. # Fast path for ASCII printable (no tabs, escapes, or control chars) if text.isascii() and text.isprintable(): return len(text) # Fast parse: if no horizontal cursor movements are possible, switch to 'ignore' mode. # Only check for longer strings - the detection overhead hurts short string performance. if control_codes == 'parse' and len(text) > _WIDTH_FAST_PATH_MIN_LEN: # Check for cursor-affecting control characters if '\b' not in text and '\t' not in text and '\r' not in text: # Check for escape sequences - if none, or only non-cursor-movement sequences if '\x1b' not in text or ( not CURSOR_RIGHT_SEQUENCE.search(text) and not CURSOR_LEFT_SEQUENCE.search(text) ): control_codes = 'ignore' # Fast path for ignore mode -- this is useful if you know the text is already "clean" if control_codes == 'ignore': return _width_ignored_codes(text, ambiguous_width) strict = control_codes == 'strict' # Track absolute positions: tab stops need modulo on absolute column, CR resets to 0. # Initialize max_extent to 0 so backward movement (CR, BS) won't yield negative width. current_col = 0 max_extent = 0 idx = 0 last_measured_idx = -2 # Track index of last measured char for VS16; -2 can never match idx-1 last_measured_ucs = -1 # Codepoint of last measured char (for deferred emoji check) last_was_virama = False # Virama conjunct formation state conjunct_pending = False # Deferred +1 for bare conjuncts (no trailing Mc) text_len = len(text) # Select wcwidth call pattern for best lru_cache performance: # - ambiguous_width=1 (default): single-arg calls share cache with direct wcwidth() calls # - ambiguous_width=2: full positional args needed (results differ, separate cache is correct) _wcwidth = wcwidth if ambiguous_width == 1 else lambda c: wcwidth(c, 'auto', ambiguous_width) while idx < text_len: char = text[idx] # 1. Handle ESC sequences if char == '\x1b': match = ZERO_WIDTH_PATTERN.match(text, idx) if match: seq = match.group() if strict and INDETERMINATE_EFFECT_SEQUENCE.match(seq): raise ValueError(f"Indeterminate cursor sequence at position {idx}") # Apply cursor movement right = CURSOR_RIGHT_SEQUENCE.match(seq) if right: current_col += int(right.group(1) or 1) else: left = CURSOR_LEFT_SEQUENCE.match(seq) if left: current_col = max(0, current_col - int(left.group(1) or 1)) idx = match.end() else: idx += 1 max_extent = max(max_extent, current_col) continue # 2. Handle illegal and vertical control characters (zero width, error in strict) if char in ILLEGAL_CTRL: if strict: raise ValueError(f"Illegal control character {ord(char):#x} at position {idx}") idx += 1 continue if char in VERTICAL_CTRL: if strict: raise ValueError(f"Vertical movement character {ord(char):#x} at position {idx}") idx += 1 continue # 3. Handle horizontal movement characters if char in HORIZONTAL_CTRL: if char == '\x09' and tabsize > 0: # Tab current_col += tabsize - (current_col % tabsize) elif char == '\x08': # Backspace if current_col > 0: current_col -= 1 elif char == '\x0d': # Carriage return current_col = 0 max_extent = max(max_extent, current_col) idx += 1 continue # 4. Handle ZWJ if char == '\u200D': if last_was_virama: # ZWJ after virama requests explicit half-form rendering but # does not change cell count — consume ZWJ only, let the next # consonant be handled by the virama conjunct rule. idx += 1 elif idx + 1 < text_len: # Emoji ZWJ: skip next character unconditionally. idx += 2 last_was_virama = False else: idx += 1 last_was_virama = False continue # 5. Handle other zero-width characters (control chars) if char in ZERO_WIDTH_CTRL: idx += 1 continue ucs = ord(char) # 6. Handle VS16: converts preceding narrow character to wide if ucs == 0xFE0F: if last_measured_idx == idx - 1: if _bisearch(ord(text[last_measured_idx]), VS16_NARROW_TO_WIDE["9.0.0"]): current_col += 1 max_extent = max(max_extent, current_col) # VS16 preserves emoji context: last_measured_ucs stays as the base idx += 1 continue # 6b. Regional Indicator & Fitzpatrick: both above BMP (U+1F1E6+) if ucs > 0xFFFF: if ucs in _REGIONAL_INDICATOR_SET: # Lazy RI pairing: count preceding consecutive RIs ri_before = 0 j = idx - 1 while j >= 0 and ord(text[j]) in _REGIONAL_INDICATOR_SET: ri_before += 1 j -= 1 if ri_before % 2 == 1: last_measured_ucs = ucs idx += 1 continue # 6c. Fitzpatrick modifier: zero-width when following emoji base elif (_FITZPATRICK_RANGE[0] <= ucs <= _FITZPATRICK_RANGE[1] and last_measured_ucs in _EMOJI_ZWJ_SET): idx += 1 continue # 7. Virama conjunct formation: consonant following virama contributes 0 width. # See https://www.unicode.org/reports/tr44/#Indic_Syllabic_Category if last_was_virama and _bisearch(ucs, _ISC_CONSONANT_TABLE): last_measured_idx = idx last_measured_ucs = ucs last_was_virama = False conjunct_pending = True idx += 1 continue # 8. Normal characters: measure with wcwidth w = _wcwidth(char) if w > 0: if conjunct_pending: current_col += 1 conjunct_pending = False current_col += w max_extent = max(max_extent, current_col) last_measured_idx = idx last_measured_ucs = ucs last_was_virama = False elif last_measured_idx >= 0 and _bisearch(ucs, _CATEGORY_MC_TABLE): # Spacing Combining Mark (Mc) following a base character adds 1 current_col += 1 max_extent = max(max_extent, current_col) last_measured_idx = -2 last_was_virama = False conjunct_pending = False else: last_was_virama = ucs in _ISC_VIRAMA_SET idx += 1 if conjunct_pending: current_col += 1 max_extent = max(max_extent, current_col) return max_extent def ljust( text: str, dest_width: int, fillchar: str = ' ', *, control_codes: Literal['parse', 'strict', 'ignore'] = 'parse', ambiguous_width: int = 1, ) -> str: r""" Return text left-justified in a string of given display width. :param text: String to justify, may contain terminal sequences. :param dest_width: Total display width of result in terminal cells. :param fillchar: Single character for padding (default space). Must have display width of 1 (not wide, not zero-width, not combining). Unicode characters like ``'·'`` are acceptable. The width is not validated. :param control_codes: How to handle control sequences when measuring. Passed to :func:`width` for measurement. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :returns: Text padded on the right to reach ``dest_width``. .. versionadded:: 0.3.0 Example:: >>> wcwidth.ljust('hi', 5) 'hi ' >>> wcwidth.ljust('\x1b[31mhi\x1b[0m', 5) '\x1b[31mhi\x1b[0m ' >>> wcwidth.ljust('\U0001F468\u200D\U0001F469\u200D\U0001F467', 6) '👨‍👩‍👧 ' """ if text.isascii() and text.isprintable(): text_width = len(text) else: text_width = width(text, control_codes=control_codes, ambiguous_width=ambiguous_width) padding_cells = max(0, dest_width - text_width) return text + fillchar * padding_cells def rjust( text: str, dest_width: int, fillchar: str = ' ', *, control_codes: Literal['parse', 'strict', 'ignore'] = 'parse', ambiguous_width: int = 1, ) -> str: r""" Return text right-justified in a string of given display width. :param text: String to justify, may contain terminal sequences. :param dest_width: Total display width of result in terminal cells. :param fillchar: Single character for padding (default space). Must have display width of 1 (not wide, not zero-width, not combining). Unicode characters like ``'·'`` are acceptable. The width is not validated. :param control_codes: How to handle control sequences when measuring. Passed to :func:`width` for measurement. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :returns: Text padded on the left to reach ``dest_width``. .. versionadded:: 0.3.0 Example:: >>> wcwidth.rjust('hi', 5) ' hi' >>> wcwidth.rjust('\x1b[31mhi\x1b[0m', 5) ' \x1b[31mhi\x1b[0m' >>> wcwidth.rjust('\U0001F468\u200D\U0001F469\u200D\U0001F467', 6) ' 👨‍👩‍👧' """ if text.isascii() and text.isprintable(): text_width = len(text) else: text_width = width(text, control_codes=control_codes, ambiguous_width=ambiguous_width) padding_cells = max(0, dest_width - text_width) return fillchar * padding_cells + text def center( text: str, dest_width: int, fillchar: str = ' ', *, control_codes: Literal['parse', 'strict', 'ignore'] = 'parse', ambiguous_width: int = 1, ) -> str: r""" Return text centered in a string of given display width. :param text: String to center, may contain terminal sequences. :param dest_width: Total display width of result in terminal cells. :param fillchar: Single character for padding (default space). Must have display width of 1 (not wide, not zero-width, not combining). Unicode characters like ``'·'`` are acceptable. The width is not validated. :param control_codes: How to handle control sequences when measuring. Passed to :func:`width` for measurement. :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :returns: Text padded on both sides to reach ``dest_width``. For odd-width padding, the extra cell goes on the right (matching Python's :meth:`str.center` behavior). .. versionadded:: 0.3.0 Example:: >>> wcwidth.center('hi', 6) ' hi ' >>> wcwidth.center('\x1b[31mhi\x1b[0m', 6) ' \x1b[31mhi\x1b[0m ' >>> wcwidth.center('\U0001F468\u200D\U0001F469\u200D\U0001F467', 6) ' 👨‍👩‍👧 ' """ if text.isascii() and text.isprintable(): text_width = len(text) else: text_width = width(text, control_codes=control_codes, ambiguous_width=ambiguous_width) total_padding = max(0, dest_width - text_width) # matching https://jazcap53.github.io/pythons-eccentric-strcenter.html left_pad = total_padding // 2 + (total_padding & dest_width & 1) right_pad = total_padding - left_pad return fillchar * left_pad + text + fillchar * right_pad def strip_sequences(text: str) -> str: r""" Return text with all terminal escape sequences removed. Unknown or incomplete ESC sequences are preserved. :param text: String that may contain terminal escape sequences. :returns: The input text with all escape sequences stripped. .. versionadded:: 0.3.0 Example:: >>> strip_sequences('\x1b[31mred\x1b[0m') 'red' >>> strip_sequences('hello') 'hello' >>> strip_sequences('\x1b[1m\x1b[31mbold red\x1b[0m text') 'bold red text' """ return ZERO_WIDTH_PATTERN.sub('', text) def clip( text: str, start: int, end: int, *, fillchar: str = ' ', tabsize: int = 8, ambiguous_width: int = 1, propagate_sgr: bool = True, ) -> str: r""" Clip text to display columns ``(start, end)`` while preserving all terminal sequences. This function extracts a substring based on visible column positions rather than character indices. Terminal escape sequences are preserved in the output since they have zero display width. If a wide character (width 2) would be split at either boundary, it is replaced with ``fillchar``. TAB characters (``\t``) are expanded to spaces up to the next tab stop, controlled by the ``tabsize`` parameter. Other cursor movement characters (backspace, carriage return) and cursor movement sequences are passed through unchanged as zero-width. :param text: String to clip, may contain terminal escape sequences. :param start: Absolute starting column (inclusive, 0-indexed). :param end: Absolute ending column (exclusive). :param fillchar: Character to use when a wide character must be split at a boundary (default space). Must have display width of 1. :param tabsize: Tab stop width (default 8). Set to 0 to pass tabs through as zero-width (preserved in output but don't advance column position). :param ambiguous_width: Width to use for East Asian Ambiguous (A) characters. Default is ``1`` (narrow). Set to ``2`` for CJK contexts. :param propagate_sgr: If True (default), SGR (terminal styling) sequences are propagated. The result begins with any active style at the start position and ends with a reset sequence if styles are active. :returns: Substring of ``text`` spanning display columns ``(start, end)``, with all terminal sequences preserved and wide characters at boundaries replaced with ``fillchar``. SGR (terminal styling) sequences are propagated by default. The result begins with any active style and ends with a reset:: >>> clip('\x1b[1;34mHello world\x1b[0m', 6, 11) '\x1b[1;34mworld\x1b[0m' Set ``propagate_sgr=False`` to disable this behavior. .. versionadded:: 0.3.0 .. versionchanged:: 0.5.0 Added ``propagate_sgr`` parameter (default True). Example:: >>> clip('hello world', 0, 5) 'hello' >>> clip('中文字', 0, 3) # Wide char split at column 3 '中 ' >>> clip('a\tb', 0, 10) # Tab expanded to spaces 'a b' """ # pylint: disable=too-complex,too-many-locals,too-many-branches,too-many-statements,too-many-nested-blocks # Again, for 'hot path', we avoid additional delegate functions and accept the cost # of complexity for improved python performance. start = max(start, 0) if end <= start: return '' # Fast path: printable ASCII only (no tabs, escape sequences, or wide or zero-width chars) if text.isascii() and text.isprintable(): return text[start:end] # Fast path: no escape sequences means no SGR tracking needed if propagate_sgr and '\x1b' not in text: propagate_sgr = False # SGR tracking state (only when propagate_sgr=True) sgr_at_clip_start = None # state when first visible char emitted (None = not yet) if propagate_sgr: sgr = _SGR_STATE_DEFAULT # current SGR state, updated by all sequences output: list[str] = [] col = 0 idx = 0 while idx < len(text): char = text[idx] # Early exit: past visible region, SGR captured, no escape ahead if col >= end and sgr_at_clip_start is not None and char != '\x1b': break # Handle escape sequences if char == '\x1b' and (match := ZERO_WIDTH_PATTERN.match(text, idx)): seq = match.group() if propagate_sgr and _SGR_PATTERN.match(seq): # Update SGR state; will be applied as prefix when visible content starts sgr = _sgr_state_update(sgr, seq) else: # Non-SGR sequences always preserved output.append(seq) idx = match.end() continue # Handle bare ESC (not a valid sequence) if char == '\x1b': output.append(char) idx += 1 continue # TAB expansion if char == '\t': if tabsize > 0: next_tab = col + (tabsize - (col % tabsize)) while col < next_tab: if start <= col < end: output.append(' ') if propagate_sgr and sgr_at_clip_start is None: sgr_at_clip_start = sgr col += 1 else: output.append(char) idx += 1 continue # Grapheme clustering for everything else grapheme = next(iter_graphemes(text, start=idx)) w = width(grapheme, ambiguous_width=ambiguous_width) if w == 0: if start <= col < end: output.append(grapheme) elif col >= start and col + w <= end: # Fully visible output.append(grapheme) if propagate_sgr and sgr_at_clip_start is None: sgr_at_clip_start = sgr col += w elif col < end and col + w > start: # Partially visible (wide char at boundary) output.append(fillchar * (min(end, col + w) - max(start, col))) if propagate_sgr and sgr_at_clip_start is None: sgr_at_clip_start = sgr col += w else: col += w idx += len(grapheme) result = ''.join(output) # Apply SGR prefix/suffix if sgr_at_clip_start is not None: if prefix := _sgr_state_to_sequence(sgr_at_clip_start): result = prefix + result if _sgr_state_is_active(sgr_at_clip_start): result += '\x1b[0m' return result