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Edit File: url.py
# engine/url.py # Copyright (C) 2005-2023 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php """Provides the :class:`~sqlalchemy.engine.url.URL` class which encapsulates information about a database connection specification. The URL object is created automatically when :func:`~sqlalchemy.engine.create_engine` is called with a string argument; alternatively, the URL is a public-facing construct which can be used directly and is also accepted directly by ``create_engine()``. """ import re from .interfaces import Dialect from .. import exc from .. import util from ..dialects import plugins from ..dialects import registry from ..util import collections_abc from ..util import compat class URL( util.namedtuple( "URL", [ "drivername", "username", "password", "host", "port", "database", "query", ], ) ): """ Represent the components of a URL used to connect to a database. URLs are typically constructed from a fully formatted URL string, where the :func:`.make_url` function is used internally by the :func:`_sa.create_engine` function in order to parse the URL string into its individual components, which are then used to construct a new :class:`.URL` object. When parsing from a formatted URL string, the parsing format generally follows `RFC-1738 <https://www.ietf.org/rfc/rfc1738.txt>`_, with some exceptions. A :class:`_engine.URL` object may also be produced directly, either by using the :func:`.make_url` function with a fully formed URL string, or by using the :meth:`_engine.URL.create` constructor in order to construct a :class:`_engine.URL` programmatically given individual fields. The resulting :class:`.URL` object may be passed directly to :func:`_sa.create_engine` in place of a string argument, which will bypass the usage of :func:`.make_url` within the engine's creation process. .. versionchanged:: 1.4 The :class:`_engine.URL` object is now an immutable object. To create a URL, use the :func:`_engine.make_url` or :meth:`_engine.URL.create` function / method. To modify a :class:`_engine.URL`, use methods like :meth:`_engine.URL.set` and :meth:`_engine.URL.update_query_dict` to return a new :class:`_engine.URL` object with modifications. See notes for this change at :ref:`change_5526`. :class:`_engine.URL` contains the following attributes: * :attr:`_engine.URL.drivername`: database backend and driver name, such as ``postgresql+psycopg2`` * :attr:`_engine.URL.username`: username string * :attr:`_engine.URL.password`: password string * :attr:`_engine.URL.host`: string hostname * :attr:`_engine.URL.port`: integer port number * :attr:`_engine.URL.database`: string database name * :attr:`_engine.URL.query`: an immutable mapping representing the query string. contains strings for keys and either strings or tuples of strings for values. """ def __new__(self, *arg, **kw): if kw.pop("_new_ok", False): return super(URL, self).__new__(self, *arg, **kw) else: util.warn_deprecated( "Calling URL() directly is deprecated and will be disabled " "in a future release. The public constructor for URL is " "now the URL.create() method.", "1.4", ) return URL.create(*arg, **kw) @classmethod def create( cls, drivername, username=None, password=None, host=None, port=None, database=None, query=util.EMPTY_DICT, ): """Create a new :class:`_engine.URL` object. :param drivername: the name of the database backend. This name will correspond to a module in sqlalchemy/databases or a third party plug-in. :param username: The user name. :param password: database password. Is typically a string, but may also be an object that can be stringified with ``str()``. .. note:: A password-producing object will be stringified only **once** per :class:`_engine.Engine` object. For dynamic password generation per connect, see :ref:`engines_dynamic_tokens`. :param host: The name of the host. :param port: The port number. :param database: The database name. :param query: A dictionary of string keys to string values to be passed to the dialect and/or the DBAPI upon connect. To specify non-string parameters to a Python DBAPI directly, use the :paramref:`_sa.create_engine.connect_args` parameter to :func:`_sa.create_engine`. See also :attr:`_engine.URL.normalized_query` for a dictionary that is consistently string->list of string. :return: new :class:`_engine.URL` object. .. versionadded:: 1.4 The :class:`_engine.URL` object is now an **immutable named tuple**. In addition, the ``query`` dictionary is also immutable. To create a URL, use the :func:`_engine.url.make_url` or :meth:`_engine.URL.create` function/ method. To modify a :class:`_engine.URL`, use the :meth:`_engine.URL.set` and :meth:`_engine.URL.update_query` methods. """ return cls( cls._assert_str(drivername, "drivername"), cls._assert_none_str(username, "username"), password, cls._assert_none_str(host, "host"), cls._assert_port(port), cls._assert_none_str(database, "database"), cls._str_dict(query), _new_ok=True, ) @classmethod def _assert_port(cls, port): if port is None: return None try: return int(port) except TypeError: raise TypeError("Port argument must be an integer or None") @classmethod def _assert_str(cls, v, paramname): if not isinstance(v, compat.string_types): raise TypeError("%s must be a string" % paramname) return v @classmethod def _assert_none_str(cls, v, paramname): if v is None: return v return cls._assert_str(v, paramname) @classmethod def _str_dict(cls, dict_): if dict_ is None: return util.EMPTY_DICT def _assert_value(val): if isinstance(val, compat.string_types): return val elif isinstance(val, collections_abc.Sequence): return tuple(_assert_value(elem) for elem in val) else: raise TypeError( "Query dictionary values must be strings or " "sequences of strings" ) def _assert_str(v): if not isinstance(v, compat.string_types): raise TypeError("Query dictionary keys must be strings") return v if isinstance(dict_, collections_abc.Sequence): dict_items = dict_ else: dict_items = dict_.items() return util.immutabledict( { _assert_str(key): _assert_value( value, ) for key, value in dict_items } ) def set( self, drivername=None, username=None, password=None, host=None, port=None, database=None, query=None, ): """return a new :class:`_engine.URL` object with modifications. Values are used if they are non-None. To set a value to ``None`` explicitly, use the :meth:`_engine.URL._replace` method adapted from ``namedtuple``. :param drivername: new drivername :param username: new username :param password: new password :param host: new hostname :param port: new port :param query: new query parameters, passed a dict of string keys referring to string or sequence of string values. Fully replaces the previous list of arguments. :return: new :class:`_engine.URL` object. .. versionadded:: 1.4 .. seealso:: :meth:`_engine.URL.update_query_dict` """ kw = {} if drivername is not None: kw["drivername"] = drivername if username is not None: kw["username"] = username if password is not None: kw["password"] = password if host is not None: kw["host"] = host if port is not None: kw["port"] = port if database is not None: kw["database"] = database if query is not None: kw["query"] = query return self._replace(**kw) def _replace(self, **kw): """Override ``namedtuple._replace()`` to provide argument checking.""" if "drivername" in kw: self._assert_str(kw["drivername"], "drivername") for name in "username", "host", "database": if name in kw: self._assert_none_str(kw[name], name) if "port" in kw: self._assert_port(kw["port"]) if "query" in kw: kw["query"] = self._str_dict(kw["query"]) return super(URL, self)._replace(**kw) def update_query_string(self, query_string, append=False): """Return a new :class:`_engine.URL` object with the :attr:`_engine.URL.query` parameter dictionary updated by the given query string. E.g.:: >>> from sqlalchemy.engine import make_url >>> url = make_url("postgresql://user:pass@host/dbname") >>> url = url.update_query_string("alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt") >>> str(url) 'postgresql://user:pass@host/dbname?alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt' :param query_string: a URL escaped query string, not including the question mark. :param append: if True, parameters in the existing query string will not be removed; new parameters will be in addition to those present. If left at its default of False, keys present in the given query parameters will replace those of the existing query string. .. versionadded:: 1.4 .. seealso:: :attr:`_engine.URL.query` :meth:`_engine.URL.update_query_dict` """ # noqa: E501 return self.update_query_pairs( util.parse_qsl(query_string), append=append ) def update_query_pairs(self, key_value_pairs, append=False): """Return a new :class:`_engine.URL` object with the :attr:`_engine.URL.query` parameter dictionary updated by the given sequence of key/value pairs E.g.:: >>> from sqlalchemy.engine import make_url >>> url = make_url("postgresql://user:pass@host/dbname") >>> url = url.update_query_pairs([("alt_host", "host1"), ("alt_host", "host2"), ("ssl_cipher", "/path/to/crt")]) >>> str(url) 'postgresql://user:pass@host/dbname?alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt' :param key_value_pairs: A sequence of tuples containing two strings each. :param append: if True, parameters in the existing query string will not be removed; new parameters will be in addition to those present. If left at its default of False, keys present in the given query parameters will replace those of the existing query string. .. versionadded:: 1.4 .. seealso:: :attr:`_engine.URL.query` :meth:`_engine.URL.difference_update_query` :meth:`_engine.URL.set` """ # noqa: E501 existing_query = self.query new_keys = {} for key, value in key_value_pairs: if key in new_keys: new_keys[key] = util.to_list(new_keys[key]) new_keys[key].append(value) else: new_keys[key] = value if append: new_query = {} for k in new_keys: if k in existing_query: new_query[k] = util.to_list( existing_query[k] ) + util.to_list(new_keys[k]) else: new_query[k] = new_keys[k] new_query.update( { k: existing_query[k] for k in set(existing_query).difference(new_keys) } ) else: new_query = self.query.union(new_keys) return self.set(query=new_query) def update_query_dict(self, query_parameters, append=False): """Return a new :class:`_engine.URL` object with the :attr:`_engine.URL.query` parameter dictionary updated by the given dictionary. The dictionary typically contains string keys and string values. In order to represent a query parameter that is expressed multiple times, pass a sequence of string values. E.g.:: >>> from sqlalchemy.engine import make_url >>> url = make_url("postgresql://user:pass@host/dbname") >>> url = url.update_query_dict({"alt_host": ["host1", "host2"], "ssl_cipher": "/path/to/crt"}) >>> str(url) 'postgresql://user:pass@host/dbname?alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt' :param query_parameters: A dictionary with string keys and values that are either strings, or sequences of strings. :param append: if True, parameters in the existing query string will not be removed; new parameters will be in addition to those present. If left at its default of False, keys present in the given query parameters will replace those of the existing query string. .. versionadded:: 1.4 .. seealso:: :attr:`_engine.URL.query` :meth:`_engine.URL.update_query_string` :meth:`_engine.URL.update_query_pairs` :meth:`_engine.URL.difference_update_query` :meth:`_engine.URL.set` """ # noqa: E501 return self.update_query_pairs(query_parameters.items(), append=append) def difference_update_query(self, names): """ Remove the given names from the :attr:`_engine.URL.query` dictionary, returning the new :class:`_engine.URL`. E.g.:: url = url.difference_update_query(['foo', 'bar']) Equivalent to using :meth:`_engine.URL.set` as follows:: url = url.set( query={ key: url.query[key] for key in set(url.query).difference(['foo', 'bar']) } ) .. versionadded:: 1.4 .. seealso:: :attr:`_engine.URL.query` :meth:`_engine.URL.update_query_dict` :meth:`_engine.URL.set` """ if not set(names).intersection(self.query): return self return URL( self.drivername, self.username, self.password, self.host, self.port, self.database, util.immutabledict( { key: self.query[key] for key in set(self.query).difference(names) } ), _new_ok=True, ) @util.memoized_property def normalized_query(self): """Return the :attr:`_engine.URL.query` dictionary with values normalized into sequences. As the :attr:`_engine.URL.query` dictionary may contain either string values or sequences of string values to differentiate between parameters that are specified multiple times in the query string, code that needs to handle multiple parameters generically will wish to use this attribute so that all parameters present are presented as sequences. Inspiration is from Python's ``urllib.parse.parse_qs`` function. E.g.:: >>> from sqlalchemy.engine import make_url >>> url = make_url("postgresql://user:pass@host/dbname?alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt") >>> url.query immutabledict({'alt_host': ('host1', 'host2'), 'ssl_cipher': '/path/to/crt'}) >>> url.normalized_query immutabledict({'alt_host': ('host1', 'host2'), 'ssl_cipher': ('/path/to/crt',)}) """ # noqa: E501 return util.immutabledict( { k: (v,) if not isinstance(v, tuple) else v for k, v in self.query.items() } ) @util.deprecated( "1.4", "The :meth:`_engine.URL.__to_string__ method is deprecated and will " "be removed in a future release. Please use the " ":meth:`_engine.URL.render_as_string` method.", ) def __to_string__(self, hide_password=True): """Render this :class:`_engine.URL` object as a string. :param hide_password: Defaults to True. The password is not shown in the string unless this is set to False. """ return self.render_as_string(hide_password=hide_password) def render_as_string(self, hide_password=True): """Render this :class:`_engine.URL` object as a string. This method is used when the ``__str__()`` or ``__repr__()`` methods are used. The method directly includes additional options. :param hide_password: Defaults to True. The password is not shown in the string unless this is set to False. """ s = self.drivername + "://" if self.username is not None: s += _sqla_url_quote(self.username) if self.password is not None: s += ":" + ( "***" if hide_password else _sqla_url_quote(str(self.password)) ) s += "@" if self.host is not None: if ":" in self.host: s += "[%s]" % self.host else: s += self.host if self.port is not None: s += ":" + str(self.port) if self.database is not None: s += "/" + self.database if self.query: keys = list(self.query) keys.sort() s += "?" + "&".join( "%s=%s" % (util.quote_plus(k), util.quote_plus(element)) for k in keys for element in util.to_list(self.query[k]) ) return s def __str__(self): return self.render_as_string(hide_password=False) def __repr__(self): return self.render_as_string() def __copy__(self): return self.__class__.create( self.drivername, self.username, self.password, self.host, self.port, self.database, # note this is an immutabledict of str-> str / tuple of str, # also fully immutable. does not require deepcopy self.query, ) def __deepcopy__(self, memo): return self.__copy__() def __hash__(self): return hash(str(self)) def __eq__(self, other): return ( isinstance(other, URL) and self.drivername == other.drivername and self.username == other.username and self.password == other.password and self.host == other.host and self.database == other.database and self.query == other.query and self.port == other.port ) def __ne__(self, other): return not self == other def get_backend_name(self): """Return the backend name. This is the name that corresponds to the database backend in use, and is the portion of the :attr:`_engine.URL.drivername` that is to the left of the plus sign. """ if "+" not in self.drivername: return self.drivername else: return self.drivername.split("+")[0] def get_driver_name(self): """Return the backend name. This is the name that corresponds to the DBAPI driver in use, and is the portion of the :attr:`_engine.URL.drivername` that is to the right of the plus sign. If the :attr:`_engine.URL.drivername` does not include a plus sign, then the default :class:`_engine.Dialect` for this :class:`_engine.URL` is imported in order to get the driver name. """ if "+" not in self.drivername: return self.get_dialect().driver else: return self.drivername.split("+")[1] def _instantiate_plugins(self, kwargs): plugin_names = util.to_list(self.query.get("plugin", ())) plugin_names += kwargs.get("plugins", []) kwargs = dict(kwargs) loaded_plugins = [ plugins.load(plugin_name)(self, kwargs) for plugin_name in plugin_names ] u = self.difference_update_query(["plugin", "plugins"]) for plugin in loaded_plugins: new_u = plugin.update_url(u) if new_u is not None: u = new_u kwargs.pop("plugins", None) return u, loaded_plugins, kwargs def _get_entrypoint(self): """Return the "entry point" dialect class. This is normally the dialect itself except in the case when the returned class implements the get_dialect_cls() method. """ if "+" not in self.drivername: name = self.drivername else: name = self.drivername.replace("+", ".") cls = registry.load(name) # check for legacy dialects that # would return a module with 'dialect' as the # actual class if ( hasattr(cls, "dialect") and isinstance(cls.dialect, type) and issubclass(cls.dialect, Dialect) ): return cls.dialect else: return cls def get_dialect(self): """Return the SQLAlchemy :class:`_engine.Dialect` class corresponding to this URL's driver name. """ entrypoint = self._get_entrypoint() dialect_cls = entrypoint.get_dialect_cls(self) return dialect_cls def translate_connect_args(self, names=None, **kw): r"""Translate url attributes into a dictionary of connection arguments. Returns attributes of this url (`host`, `database`, `username`, `password`, `port`) as a plain dictionary. The attribute names are used as the keys by default. Unset or false attributes are omitted from the final dictionary. :param \**kw: Optional, alternate key names for url attributes. :param names: Deprecated. Same purpose as the keyword-based alternate names, but correlates the name to the original positionally. """ if names is not None: util.warn_deprecated( "The `URL.translate_connect_args.name`s parameter is " "deprecated. Please pass the " "alternate names as kw arguments.", "1.4", ) translated = {} attribute_names = ["host", "database", "username", "password", "port"] for sname in attribute_names: if names: name = names.pop(0) elif sname in kw: name = kw[sname] else: name = sname if name is not None and getattr(self, sname, False): if sname == "password": translated[name] = str(getattr(self, sname)) else: translated[name] = getattr(self, sname) return translated def make_url(name_or_url): """Given a string or unicode instance, produce a new URL instance. The format of the URL generally follows `RFC-1738 <https://www.ietf.org/rfc/rfc1738.txt>`_, with some exceptions, including that underscores, and not dashes or periods, are accepted within the "scheme" portion. If a :class:`.URL` object is passed, it is returned as is. """ if isinstance(name_or_url, util.string_types): return _parse_url(name_or_url) else: return name_or_url def _parse_url(name): pattern = re.compile( r""" (?P<name>[\w\+]+):// (?: (?P<username>[^:/]*) (?::(?P<password>[^@]*))? @)? (?: (?: \[(?P<ipv6host>[^/\?]+)\] | (?P<ipv4host>[^/:\?]+) )? (?::(?P<port>[^/\?]*))? )? (?:/(?P<database>[^\?]*))? (?:\?(?P<query>.*))? """, re.X, ) m = pattern.match(name) if m is not None: components = m.groupdict() if components["query"] is not None: query = {} for key, value in util.parse_qsl(components["query"]): if util.py2k: key = key.encode("ascii") if key in query: query[key] = util.to_list(query[key]) query[key].append(value) else: query[key] = value else: query = None components["query"] = query if components["username"] is not None: components["username"] = _sqla_url_unquote(components["username"]) if components["password"] is not None: components["password"] = _sqla_url_unquote(components["password"]) ipv4host = components.pop("ipv4host") ipv6host = components.pop("ipv6host") components["host"] = ipv4host or ipv6host name = components.pop("name") if components["port"]: components["port"] = int(components["port"]) return URL.create(name, **components) else: raise exc.ArgumentError( "Could not parse SQLAlchemy URL from string '%s'" % name ) def _sqla_url_quote(text): return re.sub(r"[:@/]", lambda m: "%%%X" % ord(m.group(0)), text) def _sqla_url_unquote(text): return util.unquote(text) def _parse_keyvalue_args(name): m = re.match(r"(\w+)://(.*)", name) if m is not None: (name, args) = m.group(1, 2) opts = dict(util.parse_qsl(args)) return URL(name, *opts) else: return None