临时
####

Regex Flag::

    class RegexFlag(enum.IntFlag):
        A = ASCII = 0x80          # Assume ASCII locale.
        B = BESTMATCH = 0x1000    # Best fuzzy match.
        D = DEBUG = 0x200         # Print parsed pattern.
        E = ENHANCEMATCH = 0x8000 # Attempt to improve the fit after finding the first
                                  # fuzzy match.
        F = FULLCASE = 0x4000     # Unicode full case-folding.
        I = IGNORECASE = 0x2      # Ignore case.
        L = LOCALE = 0x4          # Assume current 8-bit locale.
        M = MULTILINE = 0x8       # Make anchors look for newline.
        P = POSIX = 0x10000       # POSIX-style matching (leftmost longest).
        R = REVERSE = 0x400       # Search backwards.
        S = DOTALL = 0x10         # Make dot match newline.
        U = UNICODE = 0x20        # Assume Unicode locale.
        V0 = VERSION0 = 0x2000    # Old legacy behaviour.
        V1 = VERSION1 = 0x100     # New enhanced behaviour.
        W = WORD = 0x800          # Default Unicode word breaks.
        X = VERBOSE = 0x40        # Ignore whitespace and comments.
        T = TEMPLATE = 0x1        # Template (present because re module has it).

    # 常用Flag
    - re.I：忽略大小写。
    - re.L：使用本地化字符集。
    - re.M：多行模式，即 ^ 和 $ 匹配每行开头和结尾。
    - re.S：点号匹配换行符。
    - re.U：使用 Unicode 模式。
    - re.X：扩展模式，允许使用空格和注释。
    - re.A：ASCII 模式，只匹配 ASCII 字符。