在Python中将Unicode URL转换为ASCII(UTF-8%转义)的最佳方法?

时间:2009-04-29 21:21:26

标签: python url unicode utf-8

我想知道什么是最好的方式 - 或者如果标准库有一个简单的方法 - 将域名和路径中的Unicode字符转换为等效的ASCII URL,使用域编码为IDNA和路径%-encoded,根据RFC 3986。

我从用户那里得到一个UTF-8的URL。因此,如果他们输入http://➡.ws/♥,我会在Python中获得'http://\xe2\x9e\xa1.ws/\xe2\x99\xa5'。我想要的是ASCII版本:'http://xn--hgi.ws/%E2%99%A5'

我现在所做的是通过正则表达式将URL拆分为多个部分,然后手动对域进行IDNA编码,并使用不同的urllib.quote()调用单独编码路径和查询字符串。

# url is UTF-8 here, eg: url = u'http://➡.ws/㉌'.encode('utf-8')
match = re.match(r'([a-z]{3,5})://(.+\.[a-z0-9]{1,6})'
                 r'(:\d{1,5})?(/.*?)(\?.*)?$', url, flags=re.I)
if not match:
    raise BadURLException(url)
protocol, domain, port, path, query = match.groups()

try:
    domain = unicode(domain, 'utf-8')
except UnicodeDecodeError:
    return ''  # bad UTF-8 chars in domain
domain = domain.encode('idna')

if port is None:
    port = ''

path = urllib.quote(path)

if query is None:
    query = ''
else:
    query = urllib.quote(query, safe='=&?/')

url = protocol + '://' + domain + port + path + query
# url is ASCII here, eg: url = 'http://xn--hgi.ws/%E3%89%8C'

这是对的吗?有更好的建议吗?是否有简单的标准库函数来执行此操作?

5 个答案:

答案 0 :(得分:45)

代码:

import urlparse, urllib

def fixurl(url):
    # turn string into unicode
    if not isinstance(url,unicode):
        url = url.decode('utf8')

    # parse it
    parsed = urlparse.urlsplit(url)

    # divide the netloc further
    userpass,at,hostport = parsed.netloc.rpartition('@')
    user,colon1,pass_ = userpass.partition(':')
    host,colon2,port = hostport.partition(':')

    # encode each component
    scheme = parsed.scheme.encode('utf8')
    user = urllib.quote(user.encode('utf8'))
    colon1 = colon1.encode('utf8')
    pass_ = urllib.quote(pass_.encode('utf8'))
    at = at.encode('utf8')
    host = host.encode('idna')
    colon2 = colon2.encode('utf8')
    port = port.encode('utf8')
    path = '/'.join(  # could be encoded slashes!
        urllib.quote(urllib.unquote(pce).encode('utf8'),'')
        for pce in parsed.path.split('/')
    )
    query = urllib.quote(urllib.unquote(parsed.query).encode('utf8'),'=&?/')
    fragment = urllib.quote(urllib.unquote(parsed.fragment).encode('utf8'))

    # put it back together
    netloc = ''.join((user,colon1,pass_,at,host,colon2,port))
    return urlparse.urlunsplit((scheme,netloc,path,query,fragment))

print fixurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5')
print fixurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5/%2F')
print fixurl(u'http://Åsa:abc123@➡.ws:81/admin')
print fixurl(u'http://➡.ws/admin')

输出:

  

http://xn--hgi.ws/%E2%99%A5
  http://xn--hgi.ws/%E2%99%A5/%2F
  http://%C3%85sa:abc123@xn--hgi.ws:81/admin
  http://xn--hgi.ws/admin

了解更多:

编辑:

  • 修正了字符串中已引用字符的情况。
  • urlparse / urlunparse更改为urlsplit / urlunsplit
  • 不要使用主机名对用户和端口信息进行编码。 (谢谢Jehiah)
  • 当缺少“@”时,不要将主机/端口视为user / pass! (谢谢hupf)

答案 1 :(得分:5)

MizardX给出的代码不是100%正确。这个例子不起作用:

example.com/folder/?page=2

查看django.utils.encoding.iri_to_uri(),将unicode网址转换为ASCII网址。

http://docs.djangoproject.com/en/dev/ref/unicode/

答案 2 :(得分:2)

有一些RFC-3896 url解析工作正在进行中(例如,作为Summer Of Code的一部分)但标准库中没有任何东西,但AFAIK没有 - 并且 uri编码<事情的一面,AFAIK。所以你不妨使用MizardX的优雅方法。

答案 3 :(得分:2)

好的,有了这些注释和我自己的代码中的一些错误修复(它根本没有处理片段),我提出了以下canonurl()函数 - 返回一个规范的ASCII形式的URL:

import re
import urllib
import urlparse

def canonurl(url):
    r"""Return the canonical, ASCII-encoded form of a UTF-8 encoded URL, or ''
    if the URL looks invalid.

    >>> canonurl('    ')
    ''
    >>> canonurl('www.google.com')
    'http://www.google.com/'
    >>> canonurl('bad-utf8.com/path\xff/file')
    ''
    >>> canonurl('svn://blah.com/path/file')
    'svn://blah.com/path/file'
    >>> canonurl('1234://badscheme.com')
    ''
    >>> canonurl('bad$scheme://google.com')
    ''
    >>> canonurl('site.badtopleveldomain')
    ''
    >>> canonurl('site.com:badport')
    ''
    >>> canonurl('http://123.24.8.240/blah')
    'http://123.24.8.240/blah'
    >>> canonurl('http://123.24.8.240:1234/blah?q#f')
    'http://123.24.8.240:1234/blah?q#f'
    >>> canonurl('\xe2\x9e\xa1.ws')  # tinyarro.ws
    'http://xn--hgi.ws/'
    >>> canonurl('  http://www.google.com:80/path/file;params?query#fragment  ')
    'http://www.google.com:80/path/file;params?query#fragment'
    >>> canonurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5')
    'http://xn--hgi.ws/%E2%99%A5'
    >>> canonurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5/pa%2Fth')
    'http://xn--hgi.ws/%E2%99%A5/pa/th'
    >>> canonurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5/pa%2Fth;par%2Fams?que%2Fry=a&b=c')
    'http://xn--hgi.ws/%E2%99%A5/pa/th;par/ams?que/ry=a&b=c'
    >>> canonurl('http://\xe2\x9e\xa1.ws/\xe2\x99\xa5?\xe2\x99\xa5#\xe2\x99\xa5')
    'http://xn--hgi.ws/%E2%99%A5?%E2%99%A5#%E2%99%A5'
    >>> canonurl('http://\xe2\x9e\xa1.ws/%e2%99%a5?%E2%99%A5#%E2%99%A5')
    'http://xn--hgi.ws/%E2%99%A5?%E2%99%A5#%E2%99%A5'
    >>> canonurl('http://badutf8pcokay.com/%FF?%FE#%FF')
    'http://badutf8pcokay.com/%FF?%FE#%FF'
    >>> len(canonurl('google.com/' + 'a' * 16384))
    4096
    """
    # strip spaces at the ends and ensure it's prefixed with 'scheme://'
    url = url.strip()
    if not url:
        return ''
    if not urlparse.urlsplit(url).scheme:
        url = 'http://' + url

    # turn it into Unicode
    try:
        url = unicode(url, 'utf-8')
    except UnicodeDecodeError:
        return ''  # bad UTF-8 chars in URL

    # parse the URL into its components
    parsed = urlparse.urlsplit(url)
    scheme, netloc, path, query, fragment = parsed

    # ensure scheme is a letter followed by letters, digits, and '+-.' chars
    if not re.match(r'[a-z][-+.a-z0-9]*$', scheme, flags=re.I):
        return ''
    scheme = str(scheme)

    # ensure domain and port are valid, eg: sub.domain.<1-to-6-TLD-chars>[:port]
    match = re.match(r'(.+\.[a-z0-9]{1,6})(:\d{1,5})?$', netloc, flags=re.I)
    if not match:
        return ''
    domain, port = match.groups()
    netloc = domain + (port if port else '')
    netloc = netloc.encode('idna')

    # ensure path is valid and convert Unicode chars to %-encoded
    if not path:
        path = '/'  # eg: 'http://google.com' -> 'http://google.com/'
    path = urllib.quote(urllib.unquote(path.encode('utf-8')), safe='/;')

    # ensure query is valid
    query = urllib.quote(urllib.unquote(query.encode('utf-8')), safe='=&?/')

    # ensure fragment is valid
    fragment = urllib.quote(urllib.unquote(fragment.encode('utf-8')))

    # piece it all back together, truncating it to a maximum of 4KB
    url = urlparse.urlunsplit((scheme, netloc, path, query, fragment))
    return url[:4096]

if __name__ == '__main__':
    import doctest
    doctest.testmod()

答案 4 :(得分:0)

您可以改用urlparse.urlsplit,但除此之外,您似乎有一个非常直接的解决方案。

protocol, domain, path, query, fragment = urlparse.urlsplit(url)

(您可以通过访问返回值的命名属性来单独访问域和端口,但由于端口语法始终为ASCII,因此不受IDNA编码过程的影响。)