Function _display_width

Lib/traceback.py:976–993

Calculate the extra amount of width space the given source code segment might take if it were to be displayed on a fixed width output device. Supports wide unicode characters and emojis.

(line, offset=None)

_WIDE_CHAR_SPECIFIERS = "WF"

def _display_width(line, offset=None):
    """Calculate the extra amount of width space the given source
    code segment might take if it were to be displayed on a fixed
    width output device. Supports wide unicode characters and emojis."""

    if offset is None:
        offset = len(line)

    # Fast track for ASCII-only strings
    if line.isascii():
        return offset

    import unicodedata

    return sum(
        2 if unicodedata.east_asian_width(char) in _WIDE_CHAR_SPECIFIERS else 1
        for char in line[:offset]
    )


def _format_note(note, indent, theme):