134 lines
4.9 KiB
Python
134 lines
4.9 KiB
Python
"""
|
|
URI Normalization function:
|
|
* Always provide the URI scheme in lowercase characters.
|
|
* Always provide the host, if any, in lowercase characters.
|
|
* Only perform percent-encoding where it is essential.
|
|
* Always use uppercase A-through-F characters when percent-encoding.
|
|
* Prevent dot-segments appearing in non-relative URI paths.
|
|
* For schemes that define a default authority, use an empty authority if the
|
|
default is desired.
|
|
* For schemes that define an empty path to be equivalent to a path of "/",
|
|
use "/".
|
|
* For schemes that define a port, use an empty port if the default is desired
|
|
* All portions of the URI must be utf-8 encoded NFC from Unicode strings
|
|
|
|
implements:
|
|
http://gbiv.com/protocols/uri/rev-2002/rfc2396bis.html#canonical-form
|
|
http://www.intertwingly.net/wiki/pie/PaceCanonicalIds
|
|
|
|
inspired by:
|
|
Tony J. Ibbs, http://starship.python.net/crew/tibs/python/tji_url.py
|
|
Mark Nottingham, http://www.mnot.net/python/urlnorm.py
|
|
"""
|
|
|
|
__license__ = "Python"
|
|
|
|
import re
|
|
import unicodedata
|
|
import urlparse
|
|
from urllib import quote, unquote
|
|
|
|
default_port = {
|
|
'http': 80,
|
|
}
|
|
|
|
|
|
class Normalizer(object):
|
|
def __init__(self, regex, normalize_func):
|
|
self.regex = regex
|
|
self.normalize = normalize_func
|
|
|
|
normalizers = ( Normalizer( re.compile(r'(?:https?://)?(?:[a-zA-Z0-9\-]+\.)?(?:amazon|amzn){1}\.(?P<tld>[a-zA-Z\.]{2,})\/(gp/(?:product|offer-listing|customer-media/product-gallery)/|exec/obidos/tg/detail/-/|o/ASIN/|dp/|(?:[A-Za-z0-9\-]+)/dp/)?(?P<ASIN>[0-9A-Za-z]{10})'),
|
|
lambda m: r'http://amazon.%s/dp/%s' % (m.group('tld'), m.group('ASIN'))),
|
|
Normalizer( re.compile(r'.*waffleimages\.com.*/([0-9a-fA-F]{40})'),
|
|
lambda m: r'http://img.waffleimages.com/%s' % m.group(1) ),
|
|
Normalizer( re.compile(r'(?:youtube.*?(?:v=|/v/)|youtu\.be/|yooouuutuuube.*?id=)([-_a-z0-9]+)'),
|
|
lambda m: r'http://youtube.com/watch?v=%s' % m.group(1) ),
|
|
)
|
|
|
|
|
|
def normalize(url):
|
|
"""Normalize a URL."""
|
|
|
|
scheme, auth, path, query, fragment = urlparse.urlsplit(url.strip())
|
|
userinfo, host, port = re.search('([^@]*@)?([^:]*):?(.*)', auth).groups()
|
|
|
|
# Always provide the URI scheme in lowercase characters.
|
|
scheme = scheme.lower()
|
|
|
|
# Always provide the host, if any, in lowercase characters.
|
|
host = host.lower()
|
|
if host and host[-1] == '.':
|
|
host = host[:-1]
|
|
if host and host.startswith("www."):
|
|
if not scheme:
|
|
scheme = "http"
|
|
host = host[4:]
|
|
elif path and path.startswith("www."):
|
|
if not scheme:
|
|
scheme = "http"
|
|
path = path[4:]
|
|
|
|
# Only perform percent-encoding where it is essential.
|
|
# Always use uppercase A-through-F characters when percent-encoding.
|
|
# All portions of the URI must be utf-8 encoded NFC from Unicode strings
|
|
def clean(string):
|
|
string = unicode(unquote(string), 'utf-8', 'replace')
|
|
return unicodedata.normalize('NFC', string).encode('utf-8')
|
|
path = quote(clean(path), "~:/?#[]@!$&'()*+,;=")
|
|
fragment = quote(clean(fragment), "~")
|
|
|
|
# note care must be taken to only encode & and = characters as values
|
|
query = "&".join(["=".join([quote(clean(t), "~:/?#[]@!$'()*+,;=")
|
|
for t in q.split("=", 1)]) for q in query.split("&")])
|
|
|
|
# Prevent dot-segments appearing in non-relative URI paths.
|
|
if scheme in ["", "http", "https", "ftp", "file"]:
|
|
output = []
|
|
for input in path.split('/'):
|
|
if input == "":
|
|
if not output:
|
|
output.append(input)
|
|
elif input == ".":
|
|
pass
|
|
elif input == "..":
|
|
if len(output) > 1:
|
|
output.pop()
|
|
else:
|
|
output.append(input)
|
|
if input in ["", ".", ".."]:
|
|
output.append("")
|
|
path = '/'.join(output)
|
|
|
|
# For schemes that define a default authority, use an empty authority if
|
|
# the default is desired.
|
|
if userinfo in ["@", ":@"]:
|
|
userinfo = ""
|
|
|
|
# For schemes that define an empty path to be equivalent to a path of "/",
|
|
# use "/".
|
|
if path == "" and scheme in ["http", "https", "ftp", "file"]:
|
|
path = "/"
|
|
|
|
# For schemes that define a port, use an empty port if the default is
|
|
# desired
|
|
if port and scheme in default_port.keys():
|
|
if port.isdigit():
|
|
port = str(int(port))
|
|
if int(port) == default_port[scheme]:
|
|
port = ''
|
|
|
|
# Put it all back together again
|
|
auth = (userinfo or "") + host
|
|
if port:
|
|
auth += ":" + port
|
|
if url.endswith("#") and query == "" and fragment == "":
|
|
path += "#"
|
|
normal_url = urlparse.urlunsplit((scheme, auth, path, query,
|
|
fragment)).replace("http:///", "http://")
|
|
for norm in normalizers:
|
|
m = norm.regex.match(normal_url)
|
|
if m:
|
|
return norm.normalize(m)
|
|
return normal_url
|