width_and_alignment.py 文件源码

def string_width(string):
    """Get the visible width of a unicode string.

    Some CJK unicode characters are more than one byte unlike ASCII and latin unicode characters.

    From: https://github.com/Robpol86/terminaltables/pull/9

    :param str string: String to measure.

    :return: String's width.
    :rtype: int
    """
    # Colorclass instance.
    if hasattr(string, 'value_no_colors'):
        string = string.value_no_colors

    # Convert to unicode.
    try:
        decoded = string.decode('u8')
    except (AttributeError, UnicodeEncodeError):
        decoded = string

    width = 0
    for char in decoded:
        if unicodedata.east_asian_width(char) in ('F', 'W'):
            width += 2
        else:
            width += 1

    return width