629 lines
18 KiB
Python
629 lines
18 KiB
Python
# util/compat.py
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# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Handle Python version/platform incompatibilities."""
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import collections
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import contextlib
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import inspect
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import operator
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import platform
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import sys
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py310 = sys.version_info >= (3, 10)
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py38 = sys.version_info >= (3, 8)
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py37 = sys.version_info >= (3, 7)
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py3k = sys.version_info >= (3, 0)
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py2k = sys.version_info < (3, 0)
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pypy = platform.python_implementation() == "PyPy"
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cpython = platform.python_implementation() == "CPython"
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win32 = sys.platform.startswith("win")
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osx = sys.platform.startswith("darwin")
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arm = "aarch" in platform.machine().lower()
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has_refcount_gc = bool(cpython)
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contextmanager = contextlib.contextmanager
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dottedgetter = operator.attrgetter
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namedtuple = collections.namedtuple
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next = next # noqa
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FullArgSpec = collections.namedtuple(
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"FullArgSpec",
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[
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"args",
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"varargs",
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"varkw",
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"defaults",
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"kwonlyargs",
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"kwonlydefaults",
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"annotations",
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],
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)
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class nullcontext(object):
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"""Context manager that does no additional processing.
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Vendored from Python 3.7.
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"""
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def __init__(self, enter_result=None):
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self.enter_result = enter_result
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def __enter__(self):
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return self.enter_result
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def __exit__(self, *excinfo):
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pass
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try:
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import threading
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except ImportError:
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import dummy_threading as threading # noqa
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def inspect_getfullargspec(func):
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"""Fully vendored version of getfullargspec from Python 3.3."""
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if inspect.ismethod(func):
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func = func.__func__
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if not inspect.isfunction(func):
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raise TypeError("{!r} is not a Python function".format(func))
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co = func.__code__
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if not inspect.iscode(co):
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raise TypeError("{!r} is not a code object".format(co))
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nargs = co.co_argcount
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names = co.co_varnames
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nkwargs = co.co_kwonlyargcount if py3k else 0
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args = list(names[:nargs])
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kwonlyargs = list(names[nargs : nargs + nkwargs])
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nargs += nkwargs
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varargs = None
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if co.co_flags & inspect.CO_VARARGS:
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varargs = co.co_varnames[nargs]
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nargs = nargs + 1
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varkw = None
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if co.co_flags & inspect.CO_VARKEYWORDS:
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varkw = co.co_varnames[nargs]
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return FullArgSpec(
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args,
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varargs,
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varkw,
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func.__defaults__,
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kwonlyargs,
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func.__kwdefaults__ if py3k else None,
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func.__annotations__ if py3k else {},
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)
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if py38:
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from importlib import metadata as importlib_metadata
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else:
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import importlib_metadata # noqa
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def importlib_metadata_get(group):
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ep = importlib_metadata.entry_points()
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if hasattr(ep, "select"):
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return ep.select(group=group)
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else:
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return ep.get(group, ())
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if py3k:
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import base64
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import builtins
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import configparser
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import itertools
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import pickle
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from functools import reduce
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from io import BytesIO as byte_buffer
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from io import StringIO
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from itertools import zip_longest
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from time import perf_counter
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from urllib.parse import (
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quote_plus,
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unquote_plus,
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parse_qsl,
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quote,
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unquote,
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)
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string_types = (str,)
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binary_types = (bytes,)
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binary_type = bytes
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text_type = str
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int_types = (int,)
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iterbytes = iter
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long_type = int
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itertools_filterfalse = itertools.filterfalse
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itertools_filter = filter
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itertools_imap = map
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exec_ = getattr(builtins, "exec")
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import_ = getattr(builtins, "__import__")
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print_ = getattr(builtins, "print")
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def b(s):
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return s.encode("latin-1")
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def b64decode(x):
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return base64.b64decode(x.encode("ascii"))
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def b64encode(x):
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return base64.b64encode(x).decode("ascii")
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def decode_backslashreplace(text, encoding):
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return text.decode(encoding, errors="backslashreplace")
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def cmp(a, b):
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return (a > b) - (a < b)
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def raise_(
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exception, with_traceback=None, replace_context=None, from_=False
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):
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r"""implement "raise" with cause support.
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:param exception: exception to raise
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:param with_traceback: will call exception.with_traceback()
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:param replace_context: an as-yet-unsupported feature. This is
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an exception object which we are "replacing", e.g., it's our
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"cause" but we don't want it printed. Basically just what
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``__suppress_context__`` does but we don't want to suppress
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the enclosing context, if any. So for now we make it the
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cause.
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:param from\_: the cause. this actually sets the cause and doesn't
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hope to hide it someday.
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"""
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if with_traceback is not None:
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exception = exception.with_traceback(with_traceback)
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if from_ is not False:
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exception.__cause__ = from_
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elif replace_context is not None:
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# no good solution here, we would like to have the exception
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# have only the context of replace_context.__context__ so that the
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# intermediary exception does not change, but we can't figure
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# that out.
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exception.__cause__ = replace_context
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try:
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raise exception
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finally:
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# credit to
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# https://cosmicpercolator.com/2016/01/13/exception-leaks-in-python-2-and-3/
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# as the __traceback__ object creates a cycle
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del exception, replace_context, from_, with_traceback
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def u(s):
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return s
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def ue(s):
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return s
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from typing import TYPE_CHECKING
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# Unused. Kept for backwards compatibility.
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callable = callable # noqa
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from abc import ABC
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def _qualname(fn):
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return fn.__qualname__
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else:
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import base64
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import ConfigParser as configparser # noqa
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import itertools
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from StringIO import StringIO # noqa
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from cStringIO import StringIO as byte_buffer # noqa
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from itertools import izip_longest as zip_longest # noqa
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from time import clock as perf_counter # noqa
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from urllib import quote # noqa
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from urllib import quote_plus # noqa
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from urllib import unquote # noqa
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from urllib import unquote_plus # noqa
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from urlparse import parse_qsl # noqa
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from abc import ABCMeta
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class ABC(object):
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__metaclass__ = ABCMeta
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try:
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import cPickle as pickle
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except ImportError:
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import pickle # noqa
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string_types = (basestring,) # noqa
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binary_types = (bytes,)
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binary_type = str
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text_type = unicode # noqa
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int_types = int, long # noqa
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long_type = long # noqa
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callable = callable # noqa
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cmp = cmp # noqa
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reduce = reduce # noqa
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b64encode = base64.b64encode
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b64decode = base64.b64decode
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itertools_filterfalse = itertools.ifilterfalse
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itertools_filter = itertools.ifilter
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itertools_imap = itertools.imap
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def b(s):
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return s
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def exec_(func_text, globals_, lcl=None):
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if lcl is None:
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exec("exec func_text in globals_")
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else:
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exec("exec func_text in globals_, lcl")
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def iterbytes(buf):
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return (ord(byte) for byte in buf)
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def import_(*args):
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if len(args) == 4:
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args = args[0:3] + ([str(arg) for arg in args[3]],)
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return __import__(*args)
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def print_(*args, **kwargs):
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fp = kwargs.pop("file", sys.stdout)
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if fp is None:
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return
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for arg in enumerate(args):
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if not isinstance(arg, basestring): # noqa
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arg = str(arg)
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fp.write(arg)
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def u(s):
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# this differs from what six does, which doesn't support non-ASCII
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# strings - we only use u() with
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# literal source strings, and all our source files with non-ascii
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# in them (all are tests) are utf-8 encoded.
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return unicode(s, "utf-8") # noqa
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def ue(s):
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return unicode(s, "unicode_escape") # noqa
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def decode_backslashreplace(text, encoding):
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try:
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return text.decode(encoding)
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except UnicodeDecodeError:
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# regular "backslashreplace" for an incompatible encoding raises:
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# "TypeError: don't know how to handle UnicodeDecodeError in
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# error callback"
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return repr(text)[1:-1].decode()
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def safe_bytestring(text):
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# py2k only
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if not isinstance(text, string_types):
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return unicode(text).encode( # noqa: F821
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"ascii", errors="backslashreplace"
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)
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elif isinstance(text, unicode): # noqa: F821
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return text.encode("ascii", errors="backslashreplace")
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else:
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return text
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exec(
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"def raise_(exception, with_traceback=None, replace_context=None, "
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"from_=False):\n"
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" if with_traceback:\n"
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" raise type(exception), exception, with_traceback\n"
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" else:\n"
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" raise exception\n"
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)
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TYPE_CHECKING = False
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def _qualname(meth):
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"""return __qualname__ equivalent for a method on a class"""
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for cls in meth.im_class.__mro__:
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if meth.__name__ in cls.__dict__:
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break
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else:
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return meth.__name__
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return "%s.%s" % (cls.__name__, meth.__name__)
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if py3k:
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def _formatannotation(annotation, base_module=None):
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"""vendored from python 3.7"""
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if getattr(annotation, "__module__", None) == "typing":
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return repr(annotation).replace("typing.", "")
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if isinstance(annotation, type):
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if annotation.__module__ in ("builtins", base_module):
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return annotation.__qualname__
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return annotation.__module__ + "." + annotation.__qualname__
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return repr(annotation)
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def inspect_formatargspec(
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args,
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varargs=None,
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varkw=None,
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defaults=None,
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kwonlyargs=(),
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kwonlydefaults={},
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annotations={},
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formatarg=str,
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formatvarargs=lambda name: "*" + name,
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formatvarkw=lambda name: "**" + name,
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formatvalue=lambda value: "=" + repr(value),
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formatreturns=lambda text: " -> " + text,
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formatannotation=_formatannotation,
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):
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"""Copy formatargspec from python 3.7 standard library.
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Python 3 has deprecated formatargspec and requested that Signature
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be used instead, however this requires a full reimplementation
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of formatargspec() in terms of creating Parameter objects and such.
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Instead of introducing all the object-creation overhead and having
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to reinvent from scratch, just copy their compatibility routine.
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Ultimately we would need to rewrite our "decorator" routine completely
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which is not really worth it right now, until all Python 2.x support
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is dropped.
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"""
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def formatargandannotation(arg):
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result = formatarg(arg)
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if arg in annotations:
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result += ": " + formatannotation(annotations[arg])
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return result
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specs = []
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if defaults:
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firstdefault = len(args) - len(defaults)
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for i, arg in enumerate(args):
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spec = formatargandannotation(arg)
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if defaults and i >= firstdefault:
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spec = spec + formatvalue(defaults[i - firstdefault])
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specs.append(spec)
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if varargs is not None:
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specs.append(formatvarargs(formatargandannotation(varargs)))
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else:
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if kwonlyargs:
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specs.append("*")
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if kwonlyargs:
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for kwonlyarg in kwonlyargs:
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spec = formatargandannotation(kwonlyarg)
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if kwonlydefaults and kwonlyarg in kwonlydefaults:
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spec += formatvalue(kwonlydefaults[kwonlyarg])
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specs.append(spec)
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if varkw is not None:
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specs.append(formatvarkw(formatargandannotation(varkw)))
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result = "(" + ", ".join(specs) + ")"
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if "return" in annotations:
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result += formatreturns(formatannotation(annotations["return"]))
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return result
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else:
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from inspect import formatargspec as _inspect_formatargspec
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def inspect_formatargspec(*spec, **kw):
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# convert for a potential FullArgSpec from compat.getfullargspec()
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return _inspect_formatargspec(*spec[0:4], **kw) # noqa
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# Fix deprecation of accessing ABCs straight from collections module
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# (which will stop working in 3.8).
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if py3k:
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import collections.abc as collections_abc
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else:
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import collections as collections_abc # noqa
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if py37:
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import dataclasses
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def dataclass_fields(cls):
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"""Return a sequence of all dataclasses.Field objects associated
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with a class."""
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if dataclasses.is_dataclass(cls):
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return dataclasses.fields(cls)
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else:
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return []
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def local_dataclass_fields(cls):
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"""Return a sequence of all dataclasses.Field objects associated with
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a class, excluding those that originate from a superclass."""
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if dataclasses.is_dataclass(cls):
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super_fields = set()
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for sup in cls.__bases__:
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super_fields.update(dataclass_fields(sup))
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return [
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f for f in dataclasses.fields(cls) if f not in super_fields
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]
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else:
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return []
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else:
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def dataclass_fields(cls):
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return []
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def local_dataclass_fields(cls):
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return []
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def raise_from_cause(exception, exc_info=None):
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r"""legacy. use raise\_()"""
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if exc_info is None:
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exc_info = sys.exc_info()
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exc_type, exc_value, exc_tb = exc_info
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cause = exc_value if exc_value is not exception else None
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reraise(type(exception), exception, tb=exc_tb, cause=cause)
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|
|
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def reraise(tp, value, tb=None, cause=None):
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r"""legacy. use raise\_()"""
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raise_(value, with_traceback=tb, from_=cause)
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|
|
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def with_metaclass(meta, *bases, **kw):
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"""Create a base class with a metaclass.
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Drops the middle class upon creation.
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Source: http://lucumr.pocoo.org/2013/5/21/porting-to-python-3-redux/
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"""
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class metaclass(meta):
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__call__ = type.__call__
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__init__ = type.__init__
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def __new__(cls, name, this_bases, d):
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if this_bases is None:
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cls = type.__new__(cls, name, (), d)
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else:
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cls = meta(name, bases, d)
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|
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if hasattr(cls, "__init_subclass__") and hasattr(
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cls.__init_subclass__, "__func__"
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):
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cls.__init_subclass__.__func__(cls, **kw)
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return cls
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|
return metaclass("temporary_class", None, {})
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|
|
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|
if py3k:
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from datetime import timezone
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else:
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from datetime import datetime
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from datetime import timedelta
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from datetime import tzinfo
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class timezone(tzinfo):
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"""Minimal port of python 3 timezone object"""
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__slots__ = "_offset"
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def __init__(self, offset):
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if not isinstance(offset, timedelta):
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raise TypeError("offset must be a timedelta")
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if not self._minoffset <= offset <= self._maxoffset:
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raise ValueError(
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"offset must be a timedelta "
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"strictly between -timedelta(hours=24) and "
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"timedelta(hours=24)."
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)
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self._offset = offset
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def __eq__(self, other):
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if type(other) != timezone:
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return False
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return self._offset == other._offset
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|
|
def __hash__(self):
|
|
return hash(self._offset)
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|
|
def __repr__(self):
|
|
return "sqlalchemy.util.%s(%r)" % (
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self.__class__.__name__,
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self._offset,
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)
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|
|
def __str__(self):
|
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return self.tzname(None)
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|
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def utcoffset(self, dt):
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return self._offset
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|
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def tzname(self, dt):
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return self._name_from_offset(self._offset)
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|
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def dst(self, dt):
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return None
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|
|
|
def fromutc(self, dt):
|
|
if isinstance(dt, datetime):
|
|
if dt.tzinfo is not self:
|
|
raise ValueError("fromutc: dt.tzinfo " "is not self")
|
|
return dt + self._offset
|
|
raise TypeError(
|
|
"fromutc() argument must be a datetime instance" " or None"
|
|
)
|
|
|
|
@staticmethod
|
|
def _timedelta_to_microseconds(timedelta):
|
|
"""backport of timedelta._to_microseconds()"""
|
|
return (
|
|
timedelta.days * (24 * 3600) + timedelta.seconds
|
|
) * 1000000 + timedelta.microseconds
|
|
|
|
@staticmethod
|
|
def _divmod_timedeltas(a, b):
|
|
"""backport of timedelta.__divmod__"""
|
|
|
|
q, r = divmod(
|
|
timezone._timedelta_to_microseconds(a),
|
|
timezone._timedelta_to_microseconds(b),
|
|
)
|
|
return q, timedelta(0, 0, r)
|
|
|
|
@staticmethod
|
|
def _name_from_offset(delta):
|
|
if not delta:
|
|
return "UTC"
|
|
if delta < timedelta(0):
|
|
sign = "-"
|
|
delta = -delta
|
|
else:
|
|
sign = "+"
|
|
hours, rest = timezone._divmod_timedeltas(
|
|
delta, timedelta(hours=1)
|
|
)
|
|
minutes, rest = timezone._divmod_timedeltas(
|
|
rest, timedelta(minutes=1)
|
|
)
|
|
result = "UTC%s%02d:%02d" % (sign, hours, minutes)
|
|
if rest.seconds:
|
|
result += ":%02d" % (rest.seconds,)
|
|
if rest.microseconds:
|
|
result += ".%06d" % (rest.microseconds,)
|
|
return result
|
|
|
|
_maxoffset = timedelta(hours=23, minutes=59)
|
|
_minoffset = -_maxoffset
|
|
|
|
timezone.utc = timezone(timedelta(0))
|