Source code for boltons.urlutils

# -*- coding: utf-8 -*-
""":mod:`urlutils` is a module dedicated to one of software's most
versatile, well-aged, and beloved data structures: the URL, also known
as the `Uniform Resource Locator`_.

Among other things, this module is a full reimplementation of URLs,
without any reliance on the :mod:`urlparse` or :mod:`urllib` standard
library modules. The centerpiece and top-level interface of urlutils
is the :class:`URL` type. Also featured is the :func:`find_all_links`
convenience function. Some low-level functions and constants are also

The implementations in this module are based heavily on `RFC 3986`_ and
`RFC 3987`_, and incorporates details from several other RFCs and `W3C

.. _Uniform Resource Locator:
.. _RFC 3986:
.. _RFC 3987:
.. _W3C documents:


import re
import socket
import string
from unicodedata import normalize

unicode = type(u'')
except NameError:
    unichr = chr

# The unreserved URI characters (per RFC 3986 Section 2.3)

# URL parsing regex (based on RFC 3986 Appendix B, with modifications)
_URL_RE = re.compile(r'^((?P<scheme>[^:/?#]+):)?'

_HEX_CHAR_MAP = dict([((a + b).encode('ascii'),
                       unichr(int(a + b, 16)).encode('charmap'))
                      for a in string.hexdigits for b in string.hexdigits])
_ASCII_RE = re.compile('([\x00-\x7f]+)')

# This port list painstakingly curated by hand searching through
# and
SCHEME_PORT_MAP = {'acap': 674, 'afp': 548, 'dict': 2628, 'dns': 53,
                   'file': None, 'ftp': 21, 'git': 9418, 'gopher': 70,
                   'http': 80, 'https': 443, 'imap': 143, 'ipp': 631,
                   'ipps': 631, 'irc': 194, 'ircs': 6697, 'ldap': 389,
                   'ldaps': 636, 'mms': 1755, 'msrp': 2855, 'msrps': None,
                   'mtqp': 1038, 'nfs': 111, 'nntp': 119, 'nntps': 563,
                   'pop': 110, 'prospero': 1525, 'redis': 6379, 'rsync': 873,
                   'rtsp': 554, 'rtsps': 322, 'rtspu': 5005, 'sftp': 22,
                   'smb': 445, 'snmp': 161, 'ssh': 22, 'steam': None,
                   'svn': 3690, 'telnet': 23, 'ventrilo': 3784, 'vnc': 5900,
                   'wais': 210, 'ws': 80, 'wss': 443, 'xmpp': None}

# This list of schemes that don't use authorities is also from the link above.
NO_NETLOC_SCHEMES = set(['urn', 'about', 'bitcoin', 'blob', 'data', 'geo',
                         'magnet', 'mailto', 'news', 'pkcs11',
                         'sip', 'sips', 'tel'])
# As of Mar 11, 2017, there were 44 netloc schemes, and 13 non-netloc

# RFC 3986 section 2.2, Reserved Characters
_GEN_DELIMS = frozenset(u':/?#[]@')
_SUB_DELIMS = frozenset(u"!$&'()*+,;=")


class URLParseError(ValueError):
    """Exception inheriting from :exc:`ValueError`, raised when failing to
    parse a URL. Mostly raised on invalid ports and IPv6 addresses.


def to_unicode(obj):
        return unicode(obj)
    except UnicodeDecodeError:
        return unicode(obj, encoding=DEFAULT_ENCODING)

# regex from gruber via tornado
# doesn't support ipv6
# doesn't support mailto (netloc-less schemes)
_FIND_ALL_URL_RE = re.compile(to_unicode(r"""\b((?:([\w-]+):(/{1,3})|www[.])(?:(?:(?:[^\s&()<>]|&amp;|&quot;)*(?:[^!"#$%'()*+,.:;<=>?@\[\]^`{|}~\s]))|(?:\((?:[^\s&()]|&amp;|&quot;)*\)))+)"""))

def _make_quote_map(safe_chars):
    ret = {}
    # v is included in the dict for py3 mostly, because bytestrings
    # are iterables of ints, of course!
    for i, v in zip(range(256), range(256)):
        c = chr(v)
        if c in safe_chars:
            ret[c] = ret[v] = c
            ret[c] = ret[v] = '%{0:02X}'.format(i)
    return ret

_PATH_PART_QUOTE_MAP = _make_quote_map(_PATH_SAFE)
_QUERY_PART_QUOTE_MAP = _make_quote_map(_QUERY_SAFE)

[docs]def quote_path_part(text, full_quote=True): """ Percent-encode a single segment of a URL path. """ if full_quote: bytestr = normalize('NFC', to_unicode(text)).encode('utf8') return u''.join([_PATH_PART_QUOTE_MAP[b] for b in bytestr]) return u''.join([_PATH_PART_QUOTE_MAP[t] if t in _PATH_DELIMS else t for t in text])
[docs]def quote_query_part(text, full_quote=True): """ Percent-encode a single query string key or value. """ if full_quote: bytestr = normalize('NFC', to_unicode(text)).encode('utf8') return u''.join([_QUERY_PART_QUOTE_MAP[b] for b in bytestr]) return u''.join([_QUERY_PART_QUOTE_MAP[t] if t in _QUERY_DELIMS else t for t in text])
[docs]def quote_fragment_part(text, full_quote=True): """Quote the fragment part of the URL. Fragments don't have subdelimiters, so the whole URL fragment can be passed. """ if full_quote: bytestr = normalize('NFC', to_unicode(text)).encode('utf8') return u''.join([_FRAGMENT_QUOTE_MAP[b] for b in bytestr]) return u''.join([_FRAGMENT_QUOTE_MAP[t] if t in _FRAGMENT_DELIMS else t for t in text])
[docs]def quote_userinfo_part(text, full_quote=True): """Quote special characters in either the username or password section of the URL. Note that userinfo in URLs is considered deprecated in many circles (especially browsers), and support for percent-encoded userinfo can be spotty. """ if full_quote: bytestr = normalize('NFC', to_unicode(text)).encode('utf8') return u''.join([_USERINFO_PART_QUOTE_MAP[b] for b in bytestr]) return u''.join([_USERINFO_PART_QUOTE_MAP[t] if t in _USERINFO_DELIMS else t for t in text])
[docs]def unquote(string, encoding='utf-8', errors='replace'): """Percent-decode a string, by replacing %xx escapes with their single-character equivalent. The optional *encoding* and *errors* parameters specify how to decode percent-encoded sequences into Unicode characters, as accepted by the :meth:`bytes.decode()` method. By default, percent-encoded sequences are decoded with UTF-8, and invalid sequences are replaced by a placeholder character. >>> unquote(u'abc%20def') u'abc def' """ if '%' not in string: string.split return string if encoding is None: encoding = 'utf-8' if errors is None: errors = 'replace' bits = _ASCII_RE.split(string) res = [bits[0]] append = res.append for i in range(1, len(bits), 2): append(unquote_to_bytes(bits[i]).decode(encoding, errors)) append(bits[i + 1]) return ''.join(res)
def unquote_to_bytes(string): """unquote_to_bytes('abc%20def') -> b'abc def'.""" # Note: strings are encoded as UTF-8. This is only an issue if it contains # unescaped non-ASCII characters, which URIs should not. if not string: # Is it a string-like object? string.split return b'' if isinstance(string, unicode): string = string.encode('utf-8') bits = string.split(b'%') if len(bits) == 1: return string # import pdb;pdb.set_trace() res = [bits[0]] append = res.append for item in bits[1:]: try: append(_HEX_CHAR_MAP[item[:2]]) append(item[2:]) except KeyError: append(b'%') append(item) return b''.join(res)
[docs]def register_scheme(text, uses_netloc=None, default_port=None): """Registers new scheme information, resulting in correct port and slash behavior from the URL object. There are dozens of standard schemes preregistered, so this function is mostly meant for proprietary internal customizations or stopgaps on missing standards information. If a scheme seems to be missing, please `file an issue`_! Args: text (str): Text representing the scheme. (the 'http' in '') uses_netloc (bool): Does the scheme support specifying a network host? For instance, "http" does, "mailto" does not. default_port (int): The default port, if any, for netloc-using schemes. .. _file an issue: """ text = text.lower() if default_port is not None: try: default_port = int(default_port) except ValueError: raise ValueError('default_port expected integer or None, not %r' % (default_port,)) if uses_netloc is True: SCHEME_PORT_MAP[text] = default_port elif uses_netloc is False: if default_port is not None: raise ValueError('unexpected default port while specifying' ' non-netloc scheme: %r' % default_port) NO_NETLOC_SCHEMES.add(text) elif uses_netloc is not None: raise ValueError('uses_netloc expected True, False, or None') return
[docs]def resolve_path_parts(path_parts): """Normalize the URL path by resolving segments of '.' and '..', resulting in a dot-free path. See RFC 3986 section 5.2.4, Remove Dot Segments. """ # TODO: what to do with multiple slashes ret = [] for part in path_parts: if part == u'.': pass elif part == u'..': if ret and (len(ret) > 1 or ret[0]): # prevent unrooting ret.pop() else: ret.append(part) if list(path_parts[-1:]) in ([u'.'], [u'..']): ret.append(u'') return ret
class cachedproperty(object): """The ``cachedproperty`` is used similar to :class:`property`, except that the wrapped method is only called once. This is commonly used to implement lazy attributes. After the property has been accessed, the value is stored on the instance itself, using the same name as the cachedproperty. This allows the cache to be cleared with :func:`delattr`, or through manipulating the object's ``__dict__``. """ def __init__(self, func): self.__doc__ = getattr(func, '__doc__') self.func = func def __get__(self, obj, objtype=None): if obj is None: return self value = obj.__dict__[self.func.__name__] = self.func(obj) return value def __repr__(self): cn = self.__class__.__name__ return '<%s func=%s>' % (cn, self.func)
[docs]class URL(object): """The URL is one of the most ubiquitous data structures in the virtual and physical landscape. From blogs to billboards, URLs are so common, that it's easy to overlook their complexity and power. There are 8 parts of a URL, each with its own semantics and special characters: * :attr:`~URL.scheme` * :attr:`~URL.username` * :attr:`~URL.password` * :attr:`` * :attr:`~URL.port` * :attr:`~URL.path` * :attr:`~URL.query_params` (query string parameters) * :attr:`~URL.fragment` Each is exposed as an attribute on the URL object. RFC 3986 offers this brief structural summary of the main URL components:: foo:// \_/ \_______/ \_________/ \__/\_________/ \_________/ \__/ | | | | | | | scheme userinfo host port path query fragment And here's how that example can be manipulated with the URL type: >>> url = URL('foo://') >>> print( >>> print(url.get_authority()) >>> print(url.qp['name']) # qp is a synonym for query_params ferret URL's approach to encoding is that inputs are decoded as much as possible, and data remains in this decoded state until re-encoded using the :meth:`~URL.to_text()` method. In this way, it's similar to Python's current approach of encouraging immediate decoding of bytes to text. Note that URL instances are mutable objects. If an immutable representation of the URL is desired, the string from :meth:`~URL.to_text()` may be used. For an immutable, but almost-as-featureful, URL object, check out the `hyperlink package`_. .. _hyperlink package: """ # public attributes (for comparison, see __eq__): _cmp_attrs = ('scheme', 'uses_netloc', 'username', 'password', 'family', 'host', 'port', 'path', 'query_params', 'fragment') def __init__(self, url=''): # TODO: encoding param. The encoding that underlies the # percent-encoding is always utf8 for IRIs, but can be Latin-1 # for other usage schemes. ud = DEFAULT_PARSED_URL if url: if isinstance(url, URL): url = url.to_text() # better way to copy URLs? elif isinstance(url, bytes): try: url = url.decode(DEFAULT_ENCODING) except UnicodeDecodeError as ude: raise URLParseError('expected text or %s-encoded bytes.' ' try decoding the url bytes and' ' passing the result. (got: %s)' % (DEFAULT_ENCODING, ude)) ud = parse_url(url) _e = u'' self.scheme = ud['scheme'] or _e self._netloc_sep = ud['_netloc_sep'] or _e self.username = (unquote(ud['username']) if '%' in (ud['username'] or _e) else ud['username'] or _e) self.password = (unquote(ud['password']) if '%' in (ud['password'] or _e) else ud['password'] or _e) = ud['family'] if not ud['host']: = _e else: try: = ud['host'].encode("ascii") except UnicodeEncodeError: = ud['host'] # already non-ascii text else: ="idna") self.port = ud['port'] self.path_parts = tuple([unquote(p) if '%' in p else p for p in (ud['path'] or _e).split(u'/')]) self._query = ud['query'] or _e self.fragment = (unquote(ud['fragment']) if '%' in (ud['fragment'] or _e) else ud['fragment'] or _e) # TODO: possibly use None as marker for empty vs missing return @classmethod
[docs] def from_parts(cls, scheme=None, host=None, path_parts=(), query_params=(), fragment=u'', port=None, username=None, password=None): """Build a new URL from parts. Note that the respective arguments are not in the order they would appear in a URL: Args: scheme (str): The scheme of a URL, e.g., 'http' host (str): The host string, e.g., '' path_parts (tuple): The individual text segments of the path, e.g., ('post', '123') query_params (dict): An OMD, dict, or list of (key, value) pairs representing the keys and values of the URL's query parameters. fragment (str): The fragment of the URL, e.g., 'anchor1' port (int): The integer port of URL, automatic defaults are available for registered schemes. username (str): The username for the userinfo part of the URL. password (str): The password for the userinfo part of the URL. Note that this method does relatively little validation. :meth:`URL.to_text()` should be used to check if any errors are produced while composing the final textual URL. """ ret = cls() ret.scheme = scheme = host ret.path_parts = tuple(path_parts) or (u'',) ret.query_params.update(query_params) ret.fragment = fragment ret.port = port ret.username = username ret.password = password return ret
[docs] def query_params(self): """The parsed form of the query string of the URL, represented as a :class:`~dictutils.OrderedMultiDict`. Also available as the handy alias ``qp``. >>> url = URL('') >>> url.qp.keys() [u'utm_source', u'python'] """ return QueryParamDict.from_text(self._query)
qp = query_params @property def path(self): "The URL's path, in text form." return u'/'.join([quote_path_part(p, full_quote=False) for p in self.path_parts]) @path.setter def path(self, path_text): self.path_parts = tuple([unquote(p) if '%' in p else p for p in to_unicode(path_text).split(u'/')]) return @property def uses_netloc(self): """Whether or not a URL uses :code:`:` or :code:`://` to separate the scheme from the rest of the URL depends on the scheme's own standard definition. There is no way to infer this behavior from other parts of the URL. A scheme either supports network locations or it does not. The URL type's approach to this is to check for explicitly registered schemes, with common schemes like HTTP preregistered. This is the same approach taken by :mod:`urlparse`. URL adds two additional heuristics if the scheme as a whole is not registered. First, it attempts to check the subpart of the scheme after the last ``+`` character. This adds intuitive behavior for schemes like ``git+ssh``. Second, if a URL with an unrecognized scheme is loaded, it will maintain the separator it sees. >>> print(URL('fakescheme://').to_text()) fakescheme:// >>> print(URL('mockscheme:hello:world').to_text()) mockscheme:hello:world """ default = self._netloc_sep if self.scheme in SCHEME_PORT_MAP: return True if self.scheme in NO_NETLOC_SCHEMES: return False if self.scheme.split('+')[-1] in SCHEME_PORT_MAP: return True return default @property def default_port(self): """Return the default port for the currently-set scheme. Returns ``None`` if the scheme is unrecognized. See :func:`register_scheme` above. If :attr:`~URL.port` matches this value, no port is emitted in the output of :meth:`~URL.to_text()`. Applies the same '+' heuristic detailed in :meth:`URL.uses_netloc`. """ try: return SCHEME_PORT_MAP[self.scheme] except KeyError: return SCHEME_PORT_MAP.get(self.scheme.split('+')[-1])
[docs] def normalize(self, with_case=True): """Resolve any "." and ".." references in the path, as well as normalize scheme and host casing. To turn off case normalization, pass ``with_case=False``. More information can be found in `Section 6.2.2 of RFC 3986`_. .. _Section 6.2.2 of RFC 3986: """ self.path_parts = resolve_path_parts(self.path_parts) if with_case: self.scheme = self.scheme.lower() = return
[docs] def navigate(self, dest): """Factory method that returns a _new_ :class:`URL` based on a given destination, *dest*. Useful for navigating those relative links with ease. The newly created :class:`URL` is normalized before being returned. >>> url = URL('') >>> url.navigate('en/latest/') URL(u'') Args: dest (str): A string or URL object representing the destination More information can be found in `Section 5 of RFC 3986`_. .. _Section 5 of RFC 3986: """ orig_dest = None if not isinstance(dest, URL): dest, orig_dest = URL(dest), dest if dest.scheme and # absolute URLs replace everything, but don't make an # extra copy if we don't have to return URL(dest) if orig_dest is None else dest query_params = dest.query_params if dest.path: if dest.path.startswith(u'/'): # absolute path new_path_parts = list(dest.path_parts) else: # relative path new_path_parts = self.path_parts[:-1] + dest.path_parts else: new_path_parts = list(self.path_parts) if not query_params: query_params = self.query_params ret = self.from_parts(scheme=dest.scheme or self.scheme, or, port=dest.port or self.port, path_parts=new_path_parts, query_params=query_params, fragment=dest.fragment, username=dest.username or self.username, password=dest.password or self.password) ret.normalize() return ret
[docs] def get_authority(self, full_quote=False, with_userinfo=False): """Used by URL schemes that have a network location, :meth:`~URL.get_authority` combines :attr:`username`, :attr:`password`, :attr:`host`, and :attr:`port` into one string, the *authority*, that is used for connecting to a network-accessible resource. Used internally by :meth:`~URL.to_text()` and can be useful for labeling connections. >>> url = URL('') >>> print(url.get_authority()) >>> print(url.get_authority(with_userinfo=True)) Args: full_quote (bool): Whether or not to apply IDNA encoding. Defaults to ``False``. with_userinfo (bool): Whether or not to include username and password, technically part of the authority. Defaults to ``False``. """ parts = [] _add = parts.append if self.username and with_userinfo: _add(quote_userinfo_part(self.username)) if self.password: _add(':') _add(quote_userinfo_part(self.password)) _add('@') if if == socket.AF_INET6: _add('[') _add( _add(']') elif full_quote: _add('idna').decode('ascii')) else: _add( # TODO: 0 port? if self.port and self.port != self.default_port: _add(':') _add(unicode(self.port)) return u''.join(parts)
[docs] def to_text(self, full_quote=False): """Render a string representing the current state of the URL object. >>> url = URL('') >>> url.fragment = 'en' >>> print(url.to_text()) By setting the *full_quote* flag, the URL can either be fully quoted or minimally quoted. The most common characteristic of an encoded-URL is the presence of percent-encoded text (e.g., %60). Unquoted URLs are more readable and suitable for display, whereas fully-quoted URLs are more conservative and generally necessary for sending over the network. """ scheme = self.scheme path = u'/'.join([quote_path_part(p, full_quote=full_quote) for p in self.path_parts]) authority = self.get_authority(full_quote=full_quote, with_userinfo=True) query_string = self.query_params.to_text(full_quote=full_quote) fragment = quote_fragment_part(self.fragment, full_quote=full_quote) parts = [] _add = parts.append if scheme: _add(scheme) _add(':') if authority: _add('//') _add(authority) elif (scheme and path[:2] != '//' and self.uses_netloc): _add('//') if path: if scheme and authority and path[:1] != '/': _add('/') # TODO: i think this is here because relative paths # with absolute authorities = undefined _add(path) if query_string: _add('?') _add(query_string) if fragment: _add('#') _add(fragment) return u''.join(parts)
def __repr__(self): cn = self.__class__.__name__ return u'%s(%r)' % (cn, self.to_text()) def __eq__(self, other): for attr in self._cmp_attrs: if not getattr(self, attr) == getattr(other, attr, None): return False return True def __ne__(self, other): return not self == other
try: from socket import inet_pton except ImportError: # from import ctypes class _sockaddr(ctypes.Structure): _fields_ = [("sa_family", ctypes.c_short), ("__pad1", ctypes.c_ushort), ("ipv4_addr", ctypes.c_byte * 4), ("ipv6_addr", ctypes.c_byte * 16), ("__pad2", ctypes.c_ulong)] WSAStringToAddressA = ctypes.windll.ws2_32.WSAStringToAddressA WSAAddressToStringA = ctypes.windll.ws2_32.WSAAddressToStringA def inet_pton(address_family, ip_string): addr = _sockaddr() ip_string = ip_string.encode('ascii') addr.sa_family = address_family addr_size = ctypes.c_int(ctypes.sizeof(addr)) if WSAStringToAddressA(ip_string, address_family, None, ctypes.byref(addr), ctypes.byref(addr_size)) != 0: raise socket.error(ctypes.FormatError()) if address_family == socket.AF_INET: return ctypes.string_at(addr.ipv4_addr, 4) if address_family == socket.AF_INET6: return ctypes.string_at(addr.ipv6_addr, 16) raise socket.error('unknown address family')
[docs]def parse_host(host): """\ Low-level function used to parse the host portion of a URL. Returns a tuple of (family, host) where *family* is a :mod:`socket` module constant or ``None``, and host is a string. >>> parse_host('') == (None, '') True >>> parse_host('[::1]') == (socket.AF_INET6, '::1') True >>> parse_host('') == (socket.AF_INET, '') True Odd doctest formatting above due to py3's switch from int to enums for :mod:`socket` constants. """ if not host: return None, u'' if u':' in host and u'[' == host[0] and u']' == host[-1]: host = host[1:-1] try: inet_pton(socket.AF_INET6, host) except socket.error as se: raise URLParseError('invalid IPv6 host: %r (%r)' % (host, se)) except UnicodeEncodeError: pass # TODO: this can't be a real host right? else: family = socket.AF_INET6 return family, host try: inet_pton(socket.AF_INET, host) except (socket.error, UnicodeEncodeError): family = None # not an IP else: family = socket.AF_INET return family, host
[docs]def parse_url(url_text): """\ Used to parse the text for a single URL into a dictionary, used internally by the :class:`URL` type. Note that "URL" has a very narrow, standards-based definition. While :func:`parse_url` may raise :class:`URLParseError` under a very limited number of conditions, such as non-integer port, a surprising number of strings are technically valid URLs. For instance, the text ``"url"`` is a valid URL, because it is a relative path. In short, do not expect this function to validate form inputs or other more colloquial usages of URLs. >>> res = parse_url('') >>> sorted(res.keys()) # res is a basic dictionary ['_netloc_sep', 'authority', 'family', 'fragment', 'host', 'password', 'path', 'port', 'query', 'scheme', 'username'] """ url_text = unicode(url_text) # raise TypeError('parse_url expected text, not %r' % url_str) um = _URL_RE.match(url_text) try: gs = um.groupdict() except AttributeError: raise URLParseError('could not parse url: %r' % url_text) au_text = gs['authority'] user, pw, hostinfo = None, None, au_text if au_text: userinfo, sep, hostinfo = au_text.rpartition('@') if sep: # TODO: empty userinfo error? user, _, pw = userinfo.partition(':') host, port = None, None if hostinfo: host, sep, port_str = hostinfo.partition(u':') if sep: if u']' in port_str: host = hostinfo # wrong split, was an ipv6 else: try: port = int(port_str) except ValueError: if port_str: # empty ports ok according to RFC 3986 6.2.3 raise URLParseError('expected integer for port, not %r' % port_str) port = None family, host = parse_host(host) gs['username'] = user gs['password'] = pw gs['family'] = family gs['host'] = host gs['port'] = port return gs
DEFAULT_PARSED_URL = parse_url('')
[docs]def parse_qsl(qs, keep_blank_values=True, encoding=DEFAULT_ENCODING): """ Converts a query string into a list of (key, value) pairs. """ pairs = [s2 for s1 in qs.split('&') for s2 in s1.split(';')] ret = [] for pair in pairs: if not pair: continue key, _, value = pair.partition('=') if not value: if keep_blank_values: value = None else: continue key = unquote(key.replace('+', ' ')) if value: value = unquote(value.replace('+', ' ')) ret.append((key, value)) return ret
""" # What follows is the OrderedMultiDict from, circa # 20161021, used for the QueryParamDict, toward the bottom. """ from collections import KeysView, ValuesView, ItemsView try: from itertools import izip_longest except ImportError: from itertools import zip_longest as izip_longest try: from typeutils import make_sentinel _MISSING = make_sentinel(var_name='_MISSING') except ImportError: _MISSING = object() PREV, NEXT, KEY, VALUE, SPREV, SNEXT = range(6) class OrderedMultiDict(dict): """A MultiDict is a dictionary that can have multiple values per key and the OrderedMultiDict (OMD) is a MultiDict that retains original insertion order. Common use cases include: * handling query strings parsed from URLs * inverting a dictionary to create a reverse index (values to keys) * stacking data from multiple dictionaries in a non-destructive way The OrderedMultiDict constructor is identical to the built-in :class:`dict`, and overall the API is constitutes an intuitive superset of the built-in type: >>> omd = OrderedMultiDict() >>> omd['a'] = 1 >>> omd['b'] = 2 >>> omd.add('a', 3) >>> omd.get('a') 3 >>> omd.getlist('a') [1, 3] Some non-:class:`dict`-like behaviors also make an appearance, such as support for :func:`reversed`: >>> list(reversed(omd)) ['b', 'a'] Note that unlike some other MultiDicts, this OMD gives precedence to the most recent value added. ``omd['a']`` refers to ``3``, not ``1``. >>> omd OrderedMultiDict([('a', 1), ('b', 2), ('a', 3)]) >>> omd.poplast('a') 3 >>> omd OrderedMultiDict([('a', 1), ('b', 2)]) >>> omd.pop('a') 1 >>> omd OrderedMultiDict([('b', 2)]) Note that calling :func:`dict` on an OMD results in a dict of keys to *lists* of values: >>> from pprint import pprint as pp # ensuring proper key ordering >>> omd = OrderedMultiDict([('a', 1), ('b', 2), ('a', 3)]) >>> pp(dict(omd)) {'a': [1, 3], 'b': [2]} Note that modifying those lists will modify the OMD. If you want a safe-to-modify or flat dictionary, use :meth:`OrderedMultiDict.todict()`. >>> pp(omd.todict()) {'a': 3, 'b': 2} >>> pp(omd.todict(multi=True)) {'a': [1, 3], 'b': [2]} With ``multi=False``, items appear with the keys in to original insertion order, alongside the most-recently inserted value for that key. >>> OrderedMultiDict([('a', 1), ('b', 2), ('a', 3)]).items(multi=False) [('a', 3), ('b', 2)] """ def __init__(self, *args, **kwargs): if len(args) > 1: raise TypeError('%s expected at most 1 argument, got %s' % (self.__class__.__name__, len(args))) super(OrderedMultiDict, self).__init__() self._clear_ll() if args: self.update_extend(args[0]) if kwargs: self.update(kwargs) def _clear_ll(self): try: _map = self._map except AttributeError: _map = self._map = {} self.root = [] _map.clear() self.root[:] = [self.root, self.root, None] def _insert(self, k, v): root = self.root cells = self._map.setdefault(k, []) last = root[PREV] cell = [last, root, k, v] last[NEXT] = root[PREV] = cell cells.append(cell) def add(self, k, v): """Add a single value *v* under a key *k*. Existing values under *k* are preserved. """ values = super(OrderedMultiDict, self).setdefault(k, []) self._insert(k, v) values.append(v) def addlist(self, k, v): """Add an iterable of values underneath a specific key, preserving any values already under that key. >>> omd = OrderedMultiDict([('a', -1)]) >>> omd.addlist('a', range(3)) >>> omd OrderedMultiDict([('a', -1), ('a', 0), ('a', 1), ('a', 2)]) Called ``addlist`` for consistency with :meth:`getlist`, but tuples and other sequences and iterables work. """ self_insert = self._insert values = super(OrderedMultiDict, self).setdefault(k, []) for subv in v: self_insert(k, subv) values.extend(v) def get(self, k, default=None): """Return the value for key *k* if present in the dictionary, else *default*. If *default* is not given, ``None`` is returned. This method never raises a :exc:`KeyError`. To get all values under a key, use :meth:`OrderedMultiDict.getlist`. """ return super(OrderedMultiDict, self).get(k, [default])[-1] def getlist(self, k, default=_MISSING): """Get all values for key *k* as a list, if *k* is in the dictionary, else *default*. The list returned is a copy and can be safely mutated. If *default* is not given, an empty :class:`list` is returned. """ try: return super(OrderedMultiDict, self).__getitem__(k)[:] except KeyError: if default is _MISSING: return [] return default def clear(self): "Empty the dictionary." super(OrderedMultiDict, self).clear() self._clear_ll() def setdefault(self, k, default=_MISSING): """If key *k* is in the dictionary, return its value. If not, insert *k* with a value of *default* and return *default*. *default* defaults to ``None``. See :meth:`dict.setdefault` for more information. """ if not super(OrderedMultiDict, self).__contains__(k): self[k] = None if default is _MISSING else default return self[k] def copy(self): "Return a shallow copy of the dictionary." return self.__class__(self.iteritems(multi=True)) @classmethod def fromkeys(cls, keys, default=None): """Create a dictionary from a list of keys, with all the values set to *default*, or ``None`` if *default* is not set. """ return cls([(k, default) for k in keys]) def update(self, E, **F): """Add items from a dictionary or iterable (and/or keyword arguments), overwriting values under an existing key. See :meth:`dict.update` for more details. """ # E and F are throwback names to the dict() __doc__ if E is self: return self_add = self.add if isinstance(E, OrderedMultiDict): for k in E: if k in self: del self[k] for k, v in E.iteritems(multi=True): self_add(k, v) elif hasattr(E, 'keys'): for k in E.keys(): self[k] = E[k] else: seen = set() seen_add = seen.add for k, v in E: if k not in seen and k in self: del self[k] seen_add(k) self_add(k, v) for k in F: self[k] = F[k] return def update_extend(self, E, **F): """Add items from a dictionary, iterable, and/or keyword arguments without overwriting existing items present in the dictionary. Like :meth:`update`, but adds to existing keys instead of overwriting them. """ if E is self: iterator = iter(E.items()) elif isinstance(E, OrderedMultiDict): iterator = E.iteritems(multi=True) elif hasattr(E, 'keys'): iterator = ((k, E[k]) for k in E.keys()) else: iterator = E self_add = self.add for k, v in iterator: self_add(k, v) def __setitem__(self, k, v): if super(OrderedMultiDict, self).__contains__(k): self._remove_all(k) self._insert(k, v) super(OrderedMultiDict, self).__setitem__(k, [v]) def __getitem__(self, k): return super(OrderedMultiDict, self).__getitem__(k)[-1] def __delitem__(self, k): super(OrderedMultiDict, self).__delitem__(k) self._remove_all(k) def __eq__(self, other): if self is other: return True try: if len(other) != len(self): return False except TypeError: return False if isinstance(other, OrderedMultiDict): selfi = self.iteritems(multi=True) otheri = other.iteritems(multi=True) zipped_items = izip_longest(selfi, otheri, fillvalue=(None, None)) for (selfk, selfv), (otherk, otherv) in zipped_items: if selfk != otherk or selfv != otherv: return False if not(next(selfi, _MISSING) is _MISSING and next(otheri, _MISSING) is _MISSING): # leftovers (TODO: watch for StopIteration?) return False return True elif hasattr(other, 'keys'): for selfk in self: try: other[selfk] == self[selfk] except KeyError: return False return True return False def __ne__(self, other): return not (self == other) def pop(self, k, default=_MISSING): """Remove all values under key *k*, returning the most-recently inserted value. Raises :exc:`KeyError` if the key is not present and no *default* is provided. """ try: return self.popall(k)[-1] except KeyError: if default is _MISSING: raise KeyError(k) return default def popall(self, k, default=_MISSING): """Remove all values under key *k*, returning them in the form of a list. Raises :exc:`KeyError` if the key is not present and no *default* is provided. """ super_self = super(OrderedMultiDict, self) if super_self.__contains__(k): self._remove_all(k) if default is _MISSING: return super_self.pop(k) return super_self.pop(k, default) def poplast(self, k=_MISSING, default=_MISSING): """Remove and return the most-recently inserted value under the key *k*, or the most-recently inserted key if *k* is not provided. If no values remain under *k*, it will be removed from the OMD. Raises :exc:`KeyError` if *k* is not present in the dictionary, or the dictionary is empty. """ if k is _MISSING: if self: k = self.root[PREV][KEY] else: raise KeyError('empty %r' % type(self)) try: self._remove(k) except KeyError: if default is _MISSING: raise KeyError(k) return default values = super(OrderedMultiDict, self).__getitem__(k) v = values.pop() if not values: super(OrderedMultiDict, self).__delitem__(k) return v def _remove(self, k): values = self._map[k] cell = values.pop() cell[PREV][NEXT], cell[NEXT][PREV] = cell[NEXT], cell[PREV] if not values: del self._map[k] def _remove_all(self, k): values = self._map[k] while values: cell = values.pop() cell[PREV][NEXT], cell[NEXT][PREV] = cell[NEXT], cell[PREV] del self._map[k] def iteritems(self, multi=False): """Iterate over the OMD's items in insertion order. By default, yields only the most-recently inserted value for each key. Set *multi* to ``True`` to get all inserted items. """ root = self.root curr = root[NEXT] if multi: while curr is not root: yield curr[KEY], curr[VALUE] curr = curr[NEXT] else: for key in self.iterkeys(): yield key, self[key] def iterkeys(self, multi=False): """Iterate over the OMD's keys in insertion order. By default, yields each key once, according to the most recent insertion. Set *multi* to ``True`` to get all keys, including duplicates, in insertion order. """ root = self.root curr = root[NEXT] if multi: while curr is not root: yield curr[KEY] curr = curr[NEXT] else: yielded = set() yielded_add = yielded.add while curr is not root: k = curr[KEY] if k not in yielded: yielded_add(k) yield k curr = curr[NEXT] def itervalues(self, multi=False): """Iterate over the OMD's values in insertion order. By default, yields the most-recently inserted value per unique key. Set *multi* to ``True`` to get all values according to insertion order. """ for k, v in self.iteritems(multi=multi): yield v def todict(self, multi=False): """Gets a basic :class:`dict` of the items in this dictionary. Keys are the same as the OMD, values are the most recently inserted values for each key. Setting the *multi* arg to ``True`` is yields the same result as calling :class:`dict` on the OMD, except that all the value lists are copies that can be safely mutated. """ if multi: return dict([(k, self.getlist(k)) for k in self]) return dict([(k, self[k]) for k in self]) def sorted(self, key=None, reverse=False): """Similar to the built-in :func:`sorted`, except this method returns a new :class:`OrderedMultiDict` sorted by the provided key function, optionally reversed. Args: key (callable): A callable to determine the sort key of each element. The callable should expect an **item** (key-value pair tuple). reverse (bool): Set to ``True`` to reverse the ordering. >>> omd = OrderedMultiDict(zip(range(3), range(3))) >>> omd.sorted(reverse=True) OrderedMultiDict([(2, 2), (1, 1), (0, 0)]) Note that the key function receives an **item** (key-value tuple), so the recommended signature looks like: >>> omd = OrderedMultiDict(zip('hello', 'world')) >>> omd.sorted(key=lambda i: i[1]) # i[0] is the key, i[1] is the val OrderedMultiDict([('o', 'd'), ('l', 'l'), ('e', 'o'), ('h', 'w')]) """ cls = self.__class__ return cls(sorted(self.iteritems(), key=key, reverse=reverse)) def sortedvalues(self, key=None, reverse=False): """Returns a copy of the :class:`OrderedMultiDict` with the same keys in the same order as the original OMD, but the values within each keyspace have been sorted according to *key* and *reverse*. Args: key (callable): A single-argument callable to determine the sort key of each element. The callable should expect an **item** (key-value pair tuple). reverse (bool): Set to ``True`` to reverse the ordering. >>> omd = OrderedMultiDict() >>> omd.addlist('even', [6, 2]) >>> omd.addlist('odd', [1, 5]) >>> omd.add('even', 4) >>> omd.add('odd', 3) >>> somd = omd.sortedvalues() >>> somd.getlist('even') [2, 4, 6] >>> somd.keys(multi=True) == omd.keys(multi=True) True >>> omd == somd False >>> somd OrderedMultiDict([('even', 2), ('even', 4), ('odd', 1), ('odd', 3), ('even', 6), ('odd', 5)]) As demonstrated above, contents and key order are retained. Only value order changes. """ try: superself_iteritems = super(OrderedMultiDict, self).iteritems() except AttributeError: superself_iteritems = super(OrderedMultiDict, self).items() # (not reverse) because they pop off in reverse order for reinsertion sorted_val_map = dict([(k, sorted(v, key=key, reverse=(not reverse))) for k, v in superself_iteritems]) ret = self.__class__() for k in self.iterkeys(multi=True): ret.add(k, sorted_val_map[k].pop()) return ret def inverted(self): """Returns a new :class:`OrderedMultiDict` with values and keys swapped, like creating dictionary transposition or reverse index. Insertion order is retained and all keys and values are represented in the output. >>> omd = OMD([(0, 2), (1, 2)]) >>> omd.inverted().getlist(2) [0, 1] Inverting twice yields a copy of the original: >>> omd.inverted().inverted() OrderedMultiDict([(0, 2), (1, 2)]) """ return self.__class__((v, k) for k, v in self.iteritems(multi=True)) def counts(self): """Returns a mapping from key to number of values inserted under that key. Like :py:class:`collections.Counter`, but returns a new :class:`OrderedMultiDict`. """ # Returns an OMD because Counter/OrderedDict may not be # available, and neither Counter nor dict maintain order. super_getitem = super(OrderedMultiDict, self).__getitem__ return self.__class__((k, len(super_getitem(k))) for k in self) def keys(self, multi=False): """Returns a list containing the output of :meth:`iterkeys`. See that method's docs for more details. """ return list(self.iterkeys(multi=multi)) def values(self, multi=False): """Returns a list containing the output of :meth:`itervalues`. See that method's docs for more details. """ return list(self.itervalues(multi=multi)) def items(self, multi=False): """Returns a list containing the output of :meth:`iteritems`. See that method's docs for more details. """ return list(self.iteritems(multi=multi)) def __iter__(self): return self.iterkeys() def __reversed__(self): root = self.root curr = root[PREV] lengths = {} lengths_sd = lengths.setdefault get_values = super(OrderedMultiDict, self).__getitem__ while curr is not root: k = curr[KEY] vals = get_values(k) if lengths_sd(k, 1) == len(vals): yield k lengths[k] += 1 curr = curr[PREV] def __repr__(self): cn = self.__class__.__name__ kvs = ', '.join([repr((k, v)) for k, v in self.iteritems(multi=True)]) return '%s([%s])' % (cn, kvs) def viewkeys(self): "OMD.viewkeys() -> a set-like object providing a view on OMD's keys" return KeysView(self) def viewvalues(self): "OMD.viewvalues() -> an object providing a view on OMD's values" return ValuesView(self) def viewitems(self): "OMD.viewitems() -> a set-like object providing a view on OMD's items" return ItemsView(self) try: # try to import the built-in one anyways from boltons.dictutils import OrderedMultiDict except ImportError: pass OMD = OrderedMultiDict
[docs]class QueryParamDict(OrderedMultiDict): """A subclass of :class:`~dictutils.OrderedMultiDict` specialized for representing query string values. Everything is fully unquoted on load and all parsed keys and values are strings by default. As the name suggests, multiple values are supported and insertion order is preserved. >>> qp = QueryParamDict.from_text(u'key=val1&key=val2&utm_source=rtd') >>> qp.getlist('key') [u'val1', u'val2'] >>> qp['key'] u'val2' >>> qp.add('key', 'val3') >>> qp.to_text() 'key=val1&key=val2&utm_source=rtd&key=val3' See :class:`~dictutils.OrderedMultiDict` for more API features. """ @classmethod
[docs] def from_text(cls, query_string): """ Parse *query_string* and return a new :class:`QueryParamDict`. """ pairs = parse_qsl(query_string, keep_blank_values=True) return cls(pairs)
[docs] def to_text(self, full_quote=False): """ Render and return a query string. Args: full_quote (bool): Whether or not to percent-quote special characters or leave them decoded for readability. """ ret_list = [] for k, v in self.iteritems(multi=True): key = quote_query_part(to_unicode(k), full_quote=full_quote) if v is None: ret_list.append(key) else: val = quote_query_part(to_unicode(v), full_quote=full_quote) ret_list.append(u'='.join((key, val))) return u'&'.join(ret_list)
# TODO: cleanup OMD/cachedproperty etc.? # end