我正在使用Python和Flask在一个简单的网页上工作，并遇到此错误。我遇到了障碍，似乎无法弄清楚代码出了什么问题。
尝试登录时发生错误。所有其他功能均按预期工作。一旦按下登录按钮，错误就会弹出。
错误：
127.0.0.1 - - [23/Oct/2018 17:14:46] "POST /login HTTP/1.1" 500 -
Traceback (most recent call last):
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 2309, in __call__
return self.wsgi_app(environ, start_response)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 2295, in wsgi_app
response = self.handle_exception(e)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 1741, in handle_exception
reraise(exc_type, exc_value, tb)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\_compat.py", line 35, in reraise
raise value
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 1816, in full_dispatch_request
return self.finalize_request(rv)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 1833, in finalize_request
response = self.process_response(response)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py", line 2114, in process_response
self.session_interface.save_session(self, ctx.session, response)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\sessions.py", line 375, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\serializer.py", line 114, in dumps
payload = want_bytes(self.dump_payload(obj))
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\url_safe.py", line 42, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\serializer.py", line 99, in dump_payload
return want_bytes(self.serializer.dumps(obj, **self.serializer_kwargs))
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\tag.py", line 296, in dumps
return dumps(self.tag(value), separators=(',', ':'))
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\__init__.py", line 179, in dumps
rv = _json.dumps(obj, **kwargs)
File "D:\Programe\Anaconda\lib\json\__init__.py", line 238, in dumps
**kw).encode(obj)
File "D:\Programe\Anaconda\lib\json\encoder.py", line 199, in encode
chunks = self.iterencode(o, _one_shot=True)
File "D:\Programe\Anaconda\lib\json\encoder.py", line 257, in iterencode
return _iterencode(o, 0)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\__init__.py", line 81, in default
return _json.JSONEncoder.default(self, o)
File "D:\Programe\Anaconda\lib\json\encoder.py", line 180, in default
o.__class__.__name__)
TypeError: Object of type 'OperationalError' is not JSON serializable
浏览器错误：
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 2309,in __call__
def __call__(self, environ, start_response):
"""The WSGI server calls the Flask application object as the
WSGI application. This calls :meth:`wsgi_app` which can be
wrapped to applying middleware."""
return self.wsgi_app(environ, start_response)
def __repr__(self):
return '<%s %r>' % (
self.__class__.__name__,
self.name,
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 2295,in wsgi_app
try:
ctx.push()
response = self.full_dispatch_request()
except Exception as e:
error = e
response = self.handle_exception(e)
except:
error = sys.exc_info()[1]
raise
return response(environ, start_response)
finally:
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 1741,in handle_exception
# if we want to repropagate the exception, we can attempt to
# raise it with the whole traceback in case we can do that
# (the function was actually called from the except part)
# otherwise, we just raise the error again
if exc_value is e:
reraise(exc_type, exc_value, tb)
else:
raise e
self.log_exception((exc_type, exc_value, tb))
if handler is None:
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\_compat.py",line 35,in reraise
from io import StringIO
def reraise(tp, value, tb=None):
if value.__traceback__ is not tb:
raise value.with_traceback(tb)
raise value
implements_to_string = _identity
else:
text_type = unicode
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 2292,in wsgi_app
ctx = self.request_context(environ)
error = None
try:
try:
ctx.push()
response = self.full_dispatch_request()
except Exception as e:
error = e
response = self.handle_exception(e)
except:
error = sys.exc_info()[1]
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 1816,in full_dispatch_request
rv = self.preprocess_request()
if rv is None:
rv = self.dispatch_request()
except Exception as e:
rv = self.handle_user_exception(e)
return self.finalize_request(rv)
def finalize_request(self, rv, from_error_handler=False):
"""Given the return value from a view function this finalizes
the request by converting it into a response and invoking the
postprocessing functions. This is invoked for both normal
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 1833,in finalize_request
:internal:
"""
response = self.make_response(rv)
try:
response = self.process_response(response)
request_finished.send(self, response=response)
except Exception:
if not from_error_handler:
raise
self.logger.exception('Request finalizing failed with an '
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\app.py",line 2114,in process_response
if None in self.after_request_funcs:
funcs = chain(funcs, reversed(self.after_request_funcs[None]))
for handler in funcs:
response = handler(response)
if not self.session_interface.is_null_session(ctx.session):
self.session_interface.save_session(self, ctx.session, response)
return response
def do_teardown_request(self, exc=_sentinel):
"""Called after the request is dispatched and the response is
returned, right before the request context is popped.
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\sessions.py",line 375,in save_session
httponly = self.get_cookie_httponly(app)
secure = self.get_cookie_secure(app)
samesite = self.get_cookie_samesite(app)
expires = self.get_expiration_time(app, session)
val = self.get_signing_serializer(app).dumps(dict(session))
response.set_cookie(
app.session_cookie_name,
val,
expires=expires,
httponly=httponly,
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\serializer.py",line 114,in dumps
def dumps(self, obj, salt=None):
"""Returns a signed string serialized with the internal
serializer. The return value can be either a byte or unicode
string depending on the format of the internal serializer.
"""
payload = want_bytes(self.dump_payload(obj))
rv = self.make_signer(salt).sign(payload)
if self.is_text_serializer:
rv = rv.decode("utf-8")
return rv
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\url_safe.py",line 42,in dump_payload
original_error=e,
)
return super(URLSafeSerializerMixin, self).load_payload(json, *args, **kwargs)
def dump_payload(self, obj):
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
is_compressed = False
compressed = zlib.compress(json)
if len(compressed) < (len(json) - 1):
json = compressed
is_compressed = True
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\itsdangerous\serializer.py",line 99,in dump_payload
def dump_payload(self, obj):
"""Dumps the encoded object. The return value is always bytes.
If the internal serializer returns text, the value will be
encoded as UTF-8.
"""
return want_bytes(self.serializer.dumps(obj, **self.serializer_kwargs))
def make_signer(self, salt=None):
"""Creates a new instance of the signer to be used. The default
implementation uses the :class:`.Signer` base class.
"""
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\tag.py",line 296,in dumps
return self.tags[key].to_python(value[key])
def dumps(self, value):
"""Tag the value and dump it to a compact JSON string."""
return dumps(self.tag(value), separators=(',', ':'))
def loads(self, value):
"""Load data from a JSON string and deserialized any tagged objects."""
return loads(value, object_hook=self.untag)
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\__init__.py",line 179,in dumps
default is controlled by the ``JSON_AS_ASCII`` configuration variable
and can be overridden by the simplejson ``ensure_ascii`` parameter.
"""
_dump_arg_defaults(kwargs)
encoding = kwargs.pop('encoding', None)
rv = _json.dumps(obj, **kwargs)
if encoding is not None and isinstance(rv, text_type):
rv = rv.encode(encoding)
return rv
File "D:\Programe\Anaconda\lib\json\__init__.py",line 238,in dumps
cls = JSONEncoder
return cls(
skipkeys=skipkeys, ensure_ascii=ensure_ascii,
check_circular=check_circular, allow_nan=allow_nan, indent=indent,
separators=separators, default=default, sort_keys=sort_keys,
**kw).encode(obj)
_default_decoder = JSONDecoder(object_hook=None, object_pairs_hook=None)
File "D:\Programe\Anaconda\lib\json\encoder.py",line 199,in encode
else:
return encode_basestring(o)
# This doesn't pass the iterator directly to ''.join() because the
# exceptions aren't as detailed. The list call should be roughly
# equivalent to the PySequence_Fast that ''.join() would do.
chunks = self.iterencode(o, _one_shot=True)
if not isinstance(chunks, (list, tuple)):
chunks = list(chunks)
return ''.join(chunks)
def iterencode(self, o, _one_shot=False):
File "D:\Programe\Anaconda\lib\json\encoder.py",line 257,in iterencode
else:
_iterencode = _make_iterencode(
markers, self.default, _encoder, self.indent, floatstr,
self.key_separator, self.item_separator, self.sort_keys,
self.skipkeys, _one_shot)
return _iterencode(o, 0)
def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
_key_separator, _item_separator, _sort_keys, _skipkeys, _one_shot,
## HACK: hand-optimized bytecode; turn globals into locals
ValueError=ValueError,
File "D:\Computing Science\Year 3\Software Engineering 2\Coursework\Software-Engineering-2-Coursework\venv\lib\site-packages\flask\json\__init__.py",line 81,in default
return http_date(o.timetuple())
if isinstance(o, uuid.UUID):
return str(o)
if hasattr(o, '__html__'):
return text_type(o.__html__())
return _json.JSONEncoder.default(self, o)
class JSONDecoder(_json.JSONDecoder):
"""The default JSON decoder. This one does not change the behavior from
the default simplejson decoder. Consult the :mod:`json` documentation
File "D:\Programe\Anaconda\lib\json\encoder.py",line 180,in default
# Let the base class default method raise the TypeError
return JSONEncoder.default(self, o)
"""
raise TypeError("Object of type '%s' is not JSON serializable" %
o.__class__.__name__)
def encode(self, o):
"""Return a JSON string representation of a Python data structure.
>>> from json.encoder import JSONEncoder
TypeError: Object of type 'OperationalError' is not JSON serializable
代码：
from flask import Flask, render_template, session, redirect,request, flash,
session, url_for
from functools import wraps
import sqlite3
from sqlite3 import Error
import pdb
app = Flask( __name__ )
app.secret_key = "super secret key"
def SQL_Connect(db_file):
try:
conn = sqlite3.connect(db_file)
return conn
except Error as e:
print(e)
return None
# SQL_Create - Create the tables for the SQL database, only needs to be ran once
def SQL_Create(conn):
cur = conn.cursor()
with open('SQL.sql') as fp:
cur.executescript(fp.read())
def SQL_Test(conn):
cur = conn.cursor()
cur.execute("SELECT * FROM users")
rows = cur.fetchall()
for row in rows:
print(row)
def SQL_GetUserByID(conn, id):
cur = conn.cursor()
cur.execute("SELECT firstname FROM users WHERE userid = " + str( id ) )
result = cur.fetchall()
# I am awful code, please fix me
return str( result[0][0] )
def SQL_Threads(conn):
cur = conn.cursor()
cur.execute("SELECT * FROM reviews")
rows = list(cur)
list_of_lists = [list(elem) for elem in rows]
for row in list_of_lists:
AuthorID = row[4]
AuthorName = SQL_GetUserByID(conn, AuthorID )
row[4] = AuthorName
return list_of_lists
def SQL_Load():
database = "database.db"
conn = SQL_Connect(database)
with conn:
# SQL_Create(conn)
SQL_Test(conn)
return conn
@app.route( "/SQL_AddUser", methods=["POST"] )
def SQL_AddUser():
Connection = SQL_Load()
firstname2 = request.form['inputName']
lastname2 = request.form['inputSurname']
email2 = request.form['inputEmail']
password2 = request.form['inputPassword']
cur = Connection.cursor()
cur.execute("INSERT INTO users (firstname, lastname, email, password) VALUES(?, ?, ?, ?)",(firstname2,lastname2,email2,password2))
Connection.commit()
session['logged_in'] = True
session['sessionEmail'] = email2
return render_template("index.html")
@app.route('/index')
@app.route("/")
def index():
Connection = SQL_Load()
LoadReviews = SQL_Threads(Connection)
Title = LoadReviews[0][1]
Date = LoadReviews[0][2]
Rating = LoadReviews[0][3]
Author = LoadReviews[0][4]
Text = LoadReviews[0][5]
return render_template( "index.html", title = Title, date = Date, rating = Rating, author = Author, text = Text )
@app.route('/login', methods=["GET", "POST"])
def login():
error = ''
try:
connection = SQL_Load()
cur = connection.cursor()
if request.method == "POST":
data = cur.execute("SELECT password FROM users WHERE email= (%s)",(request.form['inputEmail']))
if request.form['password'] == data:
session['logged_in'] = True
session['sessionEmail'] = request.form['inputEmail']
flash("You are now logged in")
return redirect(url_for("/"))
else:
error = "Invalid credentials, try again."
return render_template("login.html", error=error)
except Exception as e:
flash(e)
error = "Invalid credentials, try again."
return render_template("login.html", error=error)
@app.route('/register')
def register():
return render_template("register.html")
@app.route("/logout/")
def logout():
if 'logged_in' in session:
session.clear()
flash("You have been logged out!")
return redirect(url_for('index'))
else:
flash("You need to login first")
return redirect(url_for('login'))
if __name__ == "__main__":
app.run(debug=True)
我知道目前代码很乱，对此感到抱歉。我到处搜索，没有运气。
答案 0 :(得分：0)
您的代码中似乎有两个独立的错误，第一个是在登录功能中的sql中，第二个是在错误处理代码中，这就是为什么您看到的错误消息与初始错误无关。第一个错误是在语句中
data = cur.execute("SELECT password FROM users WHERE email= (%s)",(request.form['inputEmail']))
python sqlite3模块使用？作为参数占位符而不是％s。 execute函数的第二个参数也必须是可迭代的，因为只有一个参数，其后需要有一个逗号，以便python解释器知道周围的括号表示一个元组。下面的代码应该工作< / p>
data = cur.execute("SELECT password FROM users WHERE email= ?", (request.form['inputEmail'],))
这里的错误导致一个sqlite3.OperationalError，您将用“ Exception as e例外”语句捕获该错误。然后，您将错误对象直接传递给flask flash函数而不是字符串，因此，烧瓶错误消息表明OperationalError类型的对象不可序列化。我建议完全避免使用exception语句，而将异常处理限制为仅知道该函数中可能发生的特定异常。您可以根据烧瓶文档http://flask.pocoo.org/docs/1.0/patterns/errorpages/设置自定义错误处理程序，以处理所有意外错误，这比捕获每个函数中的所有处理程序更安全。