Python 错误：尝试通过sqlalchemy在postgresql中创建数据库时发生psycopg2.OperationalError

我正试图通过sqlalchemy在postgresql中创建一个数据库。 当我尝试运行以下代码时：

import sqlalchemy
from sqlalchemy import create_engine
from sqlalchemy import Column, Integer, String, ForeignKey, MetaData
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm.session import sessionmaker
import psycopg2

engine = create_engine('postgresql://scott:tiger@localhost/postgres')
#connection = engine.connect()
base = declarative_base()

class schedule(base):
    __tablename__ = 'schedule'
    id = Column(Integer, primary_key=True)
    time = Column(String)
    monday = Column(String)
    tuesday = Column(String)
    wednesday = Column(String)
    thursday = Column(String)
    friday = Column(String)
    saturday = Column(String)

base.metadata.create_all(engine)

我得到一个错误：psycopg2.0错误

错误回溯：

Traceback (most recent call last):
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2275, in _wrap_pool_connect
    return fn()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 363, in connect
    return _ConnectionFairy._checkout(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 760, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 492, in checkout
    rec = pool._do_get()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\impl.py", line 139, in _do_get
    self._dec_overflow()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\langhelpers.py", line 68, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\compat.py", line 153, in reraise
    raise value
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\impl.py", line 136, in _do_get
    return self._create_connection()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 308, in _create_connection
    return _ConnectionRecord(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 437, in __init__
    self.__connect(first_connect_check=True)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 639, in __connect
    connection = pool._invoke_creator(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\strategies.py", line 114, in connect
    return dialect.connect(*cargs, **cparams)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\default.py", line 481, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\psycopg2\__init__.py", line 126, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "c:\program files (x86)\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\ptvsd_launcher.py", line 119, in <module>
    vspd.debug(filename, port_num, debug_id, debug_options, run_as)
  File "c:\program files (x86)\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\Packages\ptvsd\debugger.py", line 39, in debug
    run()
  File "c:\program files (x86)\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\Packages\ptvsd\__main__.py", line 316, in run_file
    runpy.run_path(target, run_name='__main__')
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "H:\prog_vs\chatBot\chatBot\chatBot\chatBot.py", line 23, in <module>
    base.metadata.create_all(engine)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\sql\schema.py", line 4304, in create_all
    ddl.SchemaGenerator, self, checkfirst=checkfirst, tables=tables
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2045, in _run_visitor
    with self._optional_conn_ctx_manager(connection) as conn:
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\contextlib.py", line 112, in __enter__
    return next(self.gen)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2037, in _optional_conn_ctx_manager
    with self._contextual_connect() as conn:
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2239, in _contextual_connect
    self._wrap_pool_connect(self.pool.connect, None),
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2279, in _wrap_pool_connect
    e, dialect, self
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 1544, in _handle_dbapi_exception_noconnection
    util.raise_from_cause(sqlalchemy_exception, exc_info)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\compat.py", line 398, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\compat.py", line 152, in reraise
    raise value.with_traceback(tb)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\base.py", line 2275, in _wrap_pool_connect
    return fn()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 363, in connect
    return _ConnectionFairy._checkout(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 760, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 492, in checkout
    rec = pool._do_get()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\impl.py", line 139, in _do_get
    self._dec_overflow()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\langhelpers.py", line 68, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\util\compat.py", line 153, in reraise
    raise value
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\impl.py", line 136, in _do_get
    return self._create_connection()
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 308, in _create_connection
    return _ConnectionRecord(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 437, in __init__
    self.__connect(first_connect_check=True)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\pool\base.py", line 639, in __connect
    connection = pool._invoke_creator(self)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\strategies.py", line 114, in connect
    return dialect.connect(*cargs, **cparams)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\sqlalchemy\engine\default.py", line 481, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site-packages\psycopg2\__init__.py", line 126, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError)
(Background on this error at: http://sqlalche.me/e/e3q8)
Press any key to continue . . .

回溯（最近一次呼叫最后一次）：
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2275行，在_wrap\u pool\u connect中
返回fn（）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\base.py”，第363行，在connect中
返回\u连接\u签出（自我）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\37\lib\site packages\sqlalchemy\pool\base.py”，第760行，在签出中
fairy=\u ConnectionRecord.checkout（池）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\base.py”，第492行，在签出中
rec=pool.\u do\u get（）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\impl.py”，第139行，在
self._dec_overflow（）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\util\langhelpers.py”，第68行，在退出时__
兼容性（exc_类型、exc_值、exc_tb）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\37\lib\site packages\sqlalchemy\util\compat.py”，第153行，在reraise中
增值
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\impl.py”，第136行，在
返回self.\u创建\u连接（）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\37\lib\site packages\sqlalchemy\pool\base.py”，第308行，在创建连接中
返回连接记录（自身）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\base.py”，第437行，在u init中__
自我连接（第一次连接检查=真）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\base.py”，第639行，在uu connect中
连接=池。\u调用\u创建者（自身）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\strategies.py”，第114行，在connect中
返回方言。连接（*cargs，**cparams）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\default.py”，第481行，在connect中
返回self.dbapi.connect（*cargs，**cparams）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\psycopg2\\uuuu init\uuuu.py”，第126行，在connect中
连接=连接（dsn，连接工厂=连接工厂，**kwasync）
psycopg2.0错误
上述异常是以下异常的直接原因：
回溯（最近一次呼叫最后一次）：
文件“c:\program files（x86）\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\ptvsd_launcher.py”，第119行，在
debug（文件名、端口号、调试id、调试选项、运行方式）
文件“c:\program files（x86）\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\Packages\ptvsd\debugger.py”，调试中第39行
运行（）
运行文件中第316行的文件“c:\program files（x86）\microsoft visual studio\2019\enterprise\common7\ide\extensions\microsoft\python\core\Packages\ptvsd\\uuuuuuuuu main\uuuuuuuu.py”
runpy.run\u路径（目标，run\u名称=“”\uu主\uuuuuuuuuuuu'）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py”，第263行，在运行路径中
pkg_name=pkg_name，script_name=fname）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py”，第96行，在运行模块代码中
模块名称、模块规格、组件名称、脚本名称）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\runpy.py”，第85行，在运行代码中
exec（代码、运行\全局）
文件“H:\prog\u vs\chatBot\chatBot\chatBot\chatBot.py”，第23行，在
base.metadata.create_all（引擎）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\sql\schema.py”，第4304行，在create\u all中
ddl.SchemaGenerator，self，checkfirst=checkfirst，tables=tables
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2045行，在_run\u visitor中
使用self.\u可选\u连接\u ctx\u管理器（连接）作为连接：
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\contextlib.py”，第112行，输入__
返回下一个（self.gen）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2037行，在\u可选\u conn\u ctx\u管理器中
使用self.\u context\u connect（）作为连接：
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2239行，在上下文连接中
self.\u wrap\u pool\u connect（self.pool.connect，无），
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2279行，在_wrap\u pool\u connect中
e、 方言
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第1544行，在\u handle\u dbapi\u exception\u noconnection中
util.raise\u from\u cause（sqlalchemy\u异常，exc\u信息）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\37\lib\site packages\sqlalchemy\util\compat.py”，第398行，位于raise\U from\U cause中
重新释放（类型（异常），异常，tb=exc\U tb，原因=原因）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\37\lib\site packages\sqlalchemy\util\compat.py”，第152行，在reraise中
通过_回溯（tb）提升值
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\engine\base.py”，第2275行，在_wrap\u pool\u connect中
返回fn（）
文件“C:\Users\Nikola\AppData\Local\Programs\Python\Python37\lib\site packages\sqlalchemy\pool\base.py”，第363行，在connect中
返回\u连接\u签出（自我）
文件“C:\Users\Nik