Your IP : 3.137.219.213
# engine/url.py
# Copyright (C) 2005-2024 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()``.
"""
from __future__ import annotations
import collections.abc as collections_abc
import re
from typing import Any
from typing import cast
from typing import Dict
from typing import Iterable
from typing import List
from typing import Mapping
from typing import NamedTuple
from typing import Optional
from typing import overload
from typing import Sequence
from typing import Tuple
from typing import Type
from typing import Union
from urllib.parse import parse_qsl
from urllib.parse import quote
from urllib.parse import quote_plus
from urllib.parse import unquote
from .interfaces import Dialect
from .. import exc
from .. import util
from ..dialects import plugins
from ..dialects import registry
class URL(NamedTuple):
"""
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`.
.. seealso::
:ref:`database_urls`
: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.
"""
drivername: str
"""database backend and driver name, such as
``postgresql+psycopg2``
"""
username: Optional[str]
"username string"
password: Optional[str]
"""password, which is normally a string but may also be any
object that has a ``__str__()`` method."""
host: Optional[str]
"""hostname or IP number. May also be a data source name for some
drivers."""
port: Optional[int]
"""integer port number"""
database: Optional[str]
"""database name"""
query: util.immutabledict[str, Union[Tuple[str, ...], str]]
"""an immutable mapping representing the query string. contains strings
for keys and either strings or tuples of strings for values, e.g.::
>>> from sqlalchemy.engine import make_url
>>> url = make_url("postgresql+psycopg2://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'})
To create a mutable copy of this mapping, use the ``dict`` constructor::
mutable_query_opts = dict(url.query)
.. seealso::
:attr:`_engine.URL.normalized_query` - normalizes all values into sequences
for consistent processing
Methods for altering the contents of :attr:`_engine.URL.query`:
:meth:`_engine.URL.update_query_dict`
:meth:`_engine.URL.update_query_string`
:meth:`_engine.URL.update_query_pairs`
:meth:`_engine.URL.difference_update_query`
""" # noqa: E501
@classmethod
def create(
cls,
drivername: str,
username: Optional[str] = None,
password: Optional[str] = None,
host: Optional[str] = None,
port: Optional[int] = None,
database: Optional[str] = None,
query: Mapping[str, Union[Sequence[str], str]] = util.EMPTY_DICT,
) -> URL:
"""Create a new :class:`_engine.URL` object.
.. seealso::
:ref:`database_urls`
: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:: The password string should **not** be URL encoded when
passed as an argument to :meth:`_engine.URL.create`; the string
should contain the password characters exactly as they would be
typed.
.. 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),
)
@classmethod
def _assert_port(cls, port: Optional[int]) -> Optional[int]:
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: str, paramname: str) -> str:
if not isinstance(v, str):
raise TypeError("%s must be a string" % paramname)
return v
@classmethod
def _assert_none_str(
cls, v: Optional[str], paramname: str
) -> Optional[str]:
if v is None:
return v
return cls._assert_str(v, paramname)
@classmethod
def _str_dict(
cls,
dict_: Optional[
Union[
Sequence[Tuple[str, Union[Sequence[str], str]]],
Mapping[str, Union[Sequence[str], str]],
]
],
) -> util.immutabledict[str, Union[Tuple[str, ...], str]]:
if dict_ is None:
return util.EMPTY_DICT
@overload
def _assert_value(
val: str,
) -> str: ...
@overload
def _assert_value(
val: Sequence[str],
) -> Union[str, Tuple[str, ...]]: ...
def _assert_value(
val: Union[str, Sequence[str]],
) -> Union[str, Tuple[str, ...]]:
if isinstance(val, str):
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: str) -> str:
if not isinstance(v, str):
raise TypeError("Query dictionary keys must be strings")
return v
dict_items: Iterable[Tuple[str, Union[Sequence[str], str]]]
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: Optional[str] = None,
username: Optional[str] = None,
password: Optional[str] = None,
host: Optional[str] = None,
port: Optional[int] = None,
database: Optional[str] = None,
query: Optional[Mapping[str, Union[Sequence[str], str]]] = None,
) -> URL:
"""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: Dict[str, Any] = {}
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._assert_replace(**kw)
def _assert_replace(self, **kw: Any) -> URL:
"""argument checks before calling _replace()"""
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 self._replace(**kw)
def update_query_string(
self, query_string: str, append: bool = False
) -> URL:
"""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+psycopg2://user:pass@host/dbname")
>>> url = url.update_query_string("alt_host=host1&alt_host=host2&ssl_cipher=%2Fpath%2Fto%2Fcrt")
>>> str(url)
'postgresql+psycopg2://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(parse_qsl(query_string), append=append)
def update_query_pairs(
self,
key_value_pairs: Iterable[Tuple[str, Union[str, List[str]]]],
append: bool = False,
) -> URL:
"""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+psycopg2://user:pass@host/dbname")
>>> url = url.update_query_pairs([("alt_host", "host1"), ("alt_host", "host2"), ("ssl_cipher", "/path/to/crt")])
>>> str(url)
'postgresql+psycopg2://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: Dict[str, Union[str, List[str]]] = {}
for key, value in key_value_pairs:
if key in new_keys:
new_keys[key] = util.to_list(new_keys[key])
cast("List[str]", new_keys[key]).append(cast(str, value))
else:
new_keys[key] = (
list(value) if isinstance(value, (list, tuple)) else value
)
new_query: Mapping[str, Union[str, Sequence[str]]]
if append:
new_query = {}
for k in new_keys:
if k in existing_query:
new_query[k] = tuple(
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(
{
k: tuple(v) if isinstance(v, list) else v
for k, v in new_keys.items()
}
)
return self.set(query=new_query)
def update_query_dict(
self,
query_parameters: Mapping[str, Union[str, List[str]]],
append: bool = False,
) -> URL:
"""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+psycopg2://user:pass@host/dbname")
>>> url = url.update_query_dict({"alt_host": ["host1", "host2"], "ssl_cipher": "/path/to/crt"})
>>> str(url)
'postgresql+psycopg2://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: Iterable[str]) -> URL:
"""
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)
}
),
)
@property
def normalized_query(self) -> Mapping[str, Sequence[str]]:
"""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+psycopg2://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: bool = True) -> str:
"""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: bool = True) -> str:
"""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 += quote(self.username, safe=" +")
if self.password is not None:
s += ":" + (
"***"
if hide_password
else quote(str(self.password), safe=" +")
)
s += "@"
if self.host is not None:
if ":" in self.host:
s += f"[{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(
f"{quote_plus(k)}={quote_plus(element)}"
for k in keys
for element in util.to_list(self.query[k])
)
return s
def __repr__(self) -> str:
return self.render_as_string()
def __copy__(self) -> URL:
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: Any) -> URL:
return self.__copy__()
def __hash__(self) -> int:
return hash(str(self))
def __eq__(self, other: Any) -> bool:
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: Any) -> bool:
return not self == other
def get_backend_name(self) -> str:
"""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) -> str:
"""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: Mapping[str, Any]
) -> Tuple[URL, List[Any], Dict[str, Any]]:
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) -> Type[Dialect]:
"""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 cast("Type[Dialect]", cls)
def get_dialect(self, _is_async: bool = False) -> Type[Dialect]:
"""Return the SQLAlchemy :class:`_engine.Dialect` class corresponding
to this URL's driver name.
"""
entrypoint = self._get_entrypoint()
if _is_async:
dialect_cls = entrypoint.get_async_dialect_cls(self)
else:
dialect_cls = entrypoint.get_dialect_cls(self)
return dialect_cls
def translate_connect_args(
self, names: Optional[List[str]] = None, **kw: Any
) -> Dict[str, Any]:
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: Union[str, URL]) -> URL:
"""Given a string, 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.
.. seealso::
:ref:`database_urls`
"""
if isinstance(name_or_url, str):
return _parse_url(name_or_url)
elif not isinstance(name_or_url, URL) and not hasattr(
name_or_url, "_sqla_is_testing_if_this_is_a_mock_object"
):
raise exc.ArgumentError(
f"Expected string or URL object, got {name_or_url!r}"
)
else:
return name_or_url
def _parse_url(name: str) -> URL:
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()
query: Optional[Dict[str, Union[str, List[str]]]]
if components["query"] is not None:
query = {}
for key, value in parse_qsl(components["query"]):
if key in query:
query[key] = util.to_list(query[key])
cast("List[str]", query[key]).append(value)
else:
query[key] = value
else:
query = None
components["query"] = query
if components["username"] is not None:
components["username"] = unquote(components["username"])
if components["password"] is not None:
components["password"] = 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) # type: ignore
else:
raise exc.ArgumentError(
"Could not parse SQLAlchemy URL from string '%s'" % name
)