你可以看看Django框架(但要考虑到许可!)，看看他们如何从任意文本中创建一个“slug”。段代码是URL和文件名友好的。

Django文本utils定义了一个函数，slugify()，这可能是这种事情的黄金标准。本质上，他们的代码如下。

import unicodedata
import re

def slugify(value, allow_unicode=False):
    """
    Taken from https://github.com/django/django/blob/master/django/utils/text.py
    Convert to ASCII if 'allow_unicode' is False. Convert spaces or repeated
    dashes to single dashes. Remove characters that aren't alphanumerics,
    underscores, or hyphens. Convert to lowercase. Also strip leading and
    trailing whitespace, dashes, and underscores.
    """
    value = str(value)
    if allow_unicode:
        value = unicodedata.normalize('NFKC', value)
    else:
        value = unicodedata.normalize('NFKD', value).encode('ascii', 'ignore').decode('ascii')
    value = re.sub(r'[^\w\s-]', '', value.lower())
    return re.sub(r'[-\s]+', '-', value).strip('-_')

旧版本是:

def slugify(value):
    """
    Normalizes string, converts to lowercase, removes non-alpha characters,
    and converts spaces to hyphens.
    """
    import unicodedata
    value = unicodedata.normalize('NFKD', value).encode('ascii', 'ignore')
    value = unicode(re.sub('[^\w\s-]', '', value).strip().lower())
    value = unicode(re.sub('[-\s]+', '-', value))
    # ...
    return value

还有更多，但我把它省略了，因为它没有解决怠惰，而是逃避。

为什么不直接用try/except来包装“osopen”，让底层操作系统来判断文件是否有效?

这看起来工作量少得多，而且无论您使用哪种操作系统都是有效的。

为python 3.6修改的答案

import string
import unicodedata

validFilenameChars = "-_.() %s%s" % (string.ascii_letters, string.digits)
def removeDisallowedFilenameChars(filename):
    cleanedFilename = unicodedata.normalize('NFKD', filename).encode('ASCII', 'ignore')
    return ''.join(chr(c) for c in cleanedFilename if chr(c) in validFilenameChars)

给，这应该涵盖了所有的基础。它为您处理所有类型的问题，包括(但不限于)字符替换。

适用于Windows、*nix和几乎所有其他文件系统。只允许打印字符。

def txt2filename(txt, chr_set='normal'):
    """Converts txt to a valid Windows/*nix filename with printable characters only.

    args:
        txt: The str to convert.
        chr_set: 'normal', 'universal', or 'inclusive'.
            'universal':    ' -.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'
            'normal':       Every printable character exept those disallowed on Windows/*nix.
            'extended':     All 'normal' characters plus the extended character ASCII codes 128-255
    """

    FILLER = '-'

    # Step 1: Remove excluded characters.
    if chr_set == 'universal':
        # Lookups in a set are O(n) vs O(n * x) for a str.
        printables = set(' -.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz')
    else:
        if chr_set == 'normal':
            max_chr = 127
        elif chr_set == 'extended':
            max_chr = 256
        else:
            raise ValueError(f'The chr_set argument may be normal, extended or universal; not {chr_set=}')
        EXCLUDED_CHRS = set(r'<>:"/\|?*')               # Illegal characters in Windows filenames.
        EXCLUDED_CHRS.update(chr(127))                  # DEL (non-printable).
        printables = set(chr(x)
                         for x in range(32, max_chr)
                         if chr(x) not in EXCLUDED_CHRS)
    result = ''.join(x if x in printables else FILLER   # Allow printable characters only.
                     for x in txt)

    # Step 2: Device names, '.', and '..' are invalid filenames in Windows.
    DEVICE_NAMES = 'CON,PRN,AUX,NUL,COM1,COM2,COM3,COM4,' \
                   'COM5,COM6,COM7,COM8,COM9,LPT1,LPT2,' \
                   'LPT3,LPT4,LPT5,LPT6,LPT7,LPT8,LPT9,' \
                   'CONIN$,CONOUT$,..,.'.split()        # This list is an O(n) operation.
    if result in DEVICE_NAMES:
        result = f'-{result}-'

    # Step 3: Maximum length of filename is 255 bytes in Windows and Linux (other *nix flavors may allow longer names).
    result = result[:255]

    # Step 4: Windows does not allow filenames to end with '.' or ' ' or begin with ' '.
    result = re.sub(r'^[. ]', FILLER, result)
    result = re.sub(r' $', FILLER, result)

    return result

这个解决方案不需要外部库。它也替代了不可打印的文件名，因为它们并不总是容易处理。

大多数解决方案都不起作用。

“你好/世界”——>“你好世界”

“/helloworld”/ ->“helloworld”

这通常不是你想要的，比如说你要为每个链接保存html，你要为不同的网页覆盖html。

我腌字典，如:

{'helloworld': 
    (
    {'/hello/world': 'helloworld', '/helloworld/': 'helloworld1'},
    2)
    }

2表示应该追加到下一个文件名的数字。

我每次都从字典中查找文件名。如果它不在那里，我创建一个新的，如果需要追加最大的数字。

这是Windows特定路径的另一个答案，使用简单的替换，没有时髦的模块:

import re

def check_for_illegal_char(input_str):
    # remove illegal characters for Windows file names/paths 
    # (illegal filenames are a superset (41) of the illegal path names (36))
    # this is according to windows blacklist obtained with Powershell
    # from: https://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names/44750843#44750843
    #
    # PS> $enc = [system.Text.Encoding]::UTF8
    # PS> $FileNameInvalidChars = [System.IO.Path]::GetInvalidFileNameChars()
    # PS> $FileNameInvalidChars | foreach { $enc.GetBytes($_) } | Out-File -FilePath InvalidFileCharCodes.txt

    illegal = '\u0022\u003c\u003e\u007c\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007\u0008' + \
              '\u0009\u000a\u000b\u000c\u000d\u000e\u000f\u0010\u0011\u0012\u0013\u0014\u0015' + \
              '\u0016\u0017\u0018\u0019\u001a\u001b\u001c\u001d\u001e\u001f\u003a\u002a\u003f\u005c\u002f' 

    output_str, _ = re.subn('['+illegal+']','_', input_str)
    output_str = output_str.replace('\\','_')   # backslash cannot be handled by regex
    output_str = output_str.replace('..','_')   # double dots are illegal too, or at least a bad idea 
    output_str = output_str[:-1] if output_str[-1] == '.' else output_str # can't have end of line '.'

    if output_str != input_str:
        print(f"The name '{input_str}' had invalid characters, "
              f"name was modified to '{output_str}'")

    return output_str

当测试check_for_illegal_char('fas\u0003\u0004good\\..asd.')，我得到:

The name 'fas♥♦good\..asd.' had invalid characters, name was modified to 'fas__good__asd'