晋太元中,武陵人捕鱼为业。缘溪行,忘路之远近。忽逢桃花林,夹岸数百步,中无杂树,芳草鲜美,落英缤纷。渔人甚异之,复前行,欲穷其林。   林尽水源,便得一山,山有小口,仿佛若有光。便舍船,从口入。初极狭,才通人。复行数十步,豁然开朗。土地平旷,屋舍俨然,有良田、美池、桑竹之属。阡陌交通,鸡犬相闻。其中往来种作,男女衣着,悉如外人。黄发垂髫,并怡然自乐。   见渔人,乃大惊,问所从来。具答之。便要还家,设酒杀鸡作食。村中闻有此人,咸来问讯。自云先世避秦时乱,率妻子邑人来此绝境,不复出焉,遂与外人间隔。问今是何世,乃不知有汉,无论魏晋。此人一一为具言所闻,皆叹惋。余人各复延至其家,皆出酒食。停数日,辞去。此中人语云:“不足为外人道也。”(间隔 一作:隔绝)   既出,得其船,便扶向路,处处志之。及郡下,诣太守,说如此。太守即遣人随其往,寻向所志,遂迷,不复得路。   南阳刘子骥,高尚士也,闻之,欣然规往。未果,寻病终。后遂无问津者。 sh-3ll

HOME


sh-3ll 1.0
DIR:/opt/cloudlinux/venv/lib64/python3.11/site-packages/sqlalchemy/testing/
Upload File :
Current File : //opt/cloudlinux/venv/lib64/python3.11/site-packages/sqlalchemy/testing/schema.py
# testing/schema.py
# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

import sys

from . import config
from . import exclusions
from .. import event
from .. import schema
from ..util import OrderedDict


__all__ = ["Table", "Column"]

table_options = {}


def Table(*args, **kw):
    """A schema.Table wrapper/hook for dialect-specific tweaks."""

    test_opts = {k: kw.pop(k) for k in list(kw) if k.startswith("test_")}

    kw.update(table_options)

    if exclusions.against(config._current, "mysql"):
        if (
            "mysql_engine" not in kw
            and "mysql_type" not in kw
            and "autoload_with" not in kw
        ):
            if "test_needs_fk" in test_opts or "test_needs_acid" in test_opts:
                kw["mysql_engine"] = "InnoDB"
            else:
                kw["mysql_engine"] = "MyISAM"

    # Apply some default cascading rules for self-referential foreign keys.
    # MySQL InnoDB has some issues around selecting self-refs too.
    if exclusions.against(config._current, "firebird"):
        table_name = args[0]
        unpack = config.db.dialect.identifier_preparer.unformat_identifiers

        # Only going after ForeignKeys in Columns.  May need to
        # expand to ForeignKeyConstraint too.
        fks = [
            fk
            for col in args
            if isinstance(col, schema.Column)
            for fk in col.foreign_keys
        ]

        for fk in fks:
            # root around in raw spec
            ref = fk._colspec
            if isinstance(ref, schema.Column):
                name = ref.table.name
            else:
                # take just the table name: on FB there cannot be
                # a schema, so the first element is always the
                # table name, possibly followed by the field name
                name = unpack(ref)[0]
            if name == table_name:
                if fk.ondelete is None:
                    fk.ondelete = "CASCADE"
                if fk.onupdate is None:
                    fk.onupdate = "CASCADE"

    return schema.Table(*args, **kw)


def Column(*args, **kw):
    """A schema.Column wrapper/hook for dialect-specific tweaks."""

    test_opts = {k: kw.pop(k) for k in list(kw) if k.startswith("test_")}

    if not config.requirements.foreign_key_ddl.enabled_for_config(config):
        args = [arg for arg in args if not isinstance(arg, schema.ForeignKey)]

    col = schema.Column(*args, **kw)
    if test_opts.get("test_needs_autoincrement", False) and kw.get(
        "primary_key", False
    ):

        if col.default is None and col.server_default is None:
            col.autoincrement = True

        # allow any test suite to pick up on this
        col.info["test_needs_autoincrement"] = True

        # hardcoded rule for firebird, oracle; this should
        # be moved out
        if exclusions.against(config._current, "firebird", "oracle"):

            def add_seq(c, tbl):
                c._init_items(
                    schema.Sequence(
                        _truncate_name(
                            config.db.dialect, tbl.name + "_" + c.name + "_seq"
                        ),
                        optional=True,
                    )
                )

            event.listen(col, "after_parent_attach", add_seq, propagate=True)
    return col


def _truncate_name(dialect, name):
    if len(name) > dialect.max_identifier_length:
        return (
            name[0 : max(dialect.max_identifier_length - 6, 0)]
            + "_"
            + hex(hash(name) % 64)[2:]
        )
    else:
        return name


def pep435_enum(name):
    # Implements PEP 435 in the minimal fashion needed by SQLAlchemy
    __members__ = OrderedDict()

    def __init__(self, name, value, alias=None):
        self.name = name
        self.value = value
        self.__members__[name] = self
        value_to_member[value] = self
        setattr(self.__class__, name, self)
        if alias:
            self.__members__[alias] = self
            setattr(self.__class__, alias, self)

    value_to_member = {}

    @classmethod
    def get(cls, value):
        return value_to_member[value]

    someenum = type(
        name,
        (object,),
        {"__members__": __members__, "__init__": __init__, "get": get},
    )

    # getframe() trick for pickling I don't understand courtesy
    # Python namedtuple()
    try:
        module = sys._getframe(1).f_globals.get("__name__", "__main__")
    except (AttributeError, ValueError):
        pass
    if module is not None:
        someenum.__module__ = module

    return someenum