flask上传文件中文名称的处理

from werkzeug.utils import secure_filename
print(secure_filename("一级标题.png"))

print(secure_filename("kakakkak.png"))
# kakakkak.png # 纯英文的不忽视
print(secure_filename("1232233.png"))
# 1232233.png
print(secure_filename("迟迟不吃饭1232233.png"))
# 1232233.png # 看下只去除了中文字符

import os, sys, re
text_type = str
PY2 = sys.version_info[0] == 2
WIN = sys.platform.startswith('win')
_format_re = re.compile(r'$(?:(%s)|{(%s)})' % (('[a-zA-Z_][a-zA-Z0-9_]*',) * 2))
_entity_re = re.compile(r'&([^;]+);')
_filename_ascii_strip_re = re.compile(r'[^A-Za-z0-9_.-]')
_windows_device_files = ('CON', 'AUX', 'COM1', 'COM2', 'COM3', 'COM4', 'LPT1',
                         'LPT2', 'LPT3', 'PRN', 'NUL')


def (filename):
    r"""Pass it a filename and it will return a secure version of it.  This
    filename can then safely be stored on a regular file system and passed
    to :func:`os.path.join`.  The filename returned is an ASCII only string
    for maximum portability.

    On windows systems the function also makes sure that the file is not
    named after one of the special device files.

    >>> secure_filename("My cool movie.mov")
    'My_cool_movie.mov'
    >>> secure_filename("../../../etc/passwd")
    'etc_passwd'
    >>> secure_filename(u'i contain cool xfcmlxe4uts.txt')
    'i_contain_cool_umlauts.txt'

    The function might return an empty filename.  It's your responsibility
    to ensure that the filename is unique and that you generate random
    filename if the function returned an empty one.

    .. versionadded:: 0.5

    :param filename: the filename to secure
    """
    if isinstance(filename, text_type):
        from unicodedata import normalize
        # Marek Čech、Beniardá怎样变成相对应的ascii码呢, 调用下面这句
        filename = normalize('NFKD', filename).encode('ascii', 'ignore')
        if not PY2:
            filename = filename.decode('ascii')
    for sep in os.path.sep, os.path.altsep:
        if sep:
            filename = filename.replace(sep, ' ')
    filename = str(_filename_ascii_strip_re.sub('', '_'.join(
                   filename.split()))).strip('._')

    # on nt a couple of special files are present in each folder.  We
    # have to ensure that the target file is not such a filename.  In
    # this case we prepend an underline
    if os.name == 'nt' and filename and 
       filename.split('.')[0].upper() in _windows_device_files:
        filename = '_' + filename

    return filename
'''
也就是说,, 上面这个方法只支持`a-zA-Z0-9.`这几种字符, 只支持ascii字符
'''

class str(object):
    def encode(self, encoding='utf-8', errors='strict'): # real signature unknown; restored from __doc__
        """
        S.encode(encoding='utf-8', errors='strict') -> bytes

        Encode S using the codec registered for encoding. Default encoding
        is 'utf-8'. errors may be given to set a different error
        handling scheme. Default is 'strict' meaning that encoding errors raise
        a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
        'xmlcharrefreplace' as well as any other name registered with
        codecs.register_error that can handle UnicodeEncodeErrors.
        """
        return b""

"迟迟不吃饭1232233.png".encode('ascii', 'strict')
# Traceback (most recent call last):
#   File "<input>", line 1, in <module>
# UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-4: ordinal not in range(128)
"迟迟不吃饭1232233.png".encode('ascii', 'replace')
# b'?????1232233.png'
"迟迟不吃饭1232233.png".encode('ascii', 'xmlcharrefreplace')
# b'&#36831;&#36831;&#19981;&#21507;&#39277;1232233.png'