退出OSError服务器在app.run(debug=True)时引发“app.run：[Errno 9]坏文件描述符”
退出OSError服务器在app.run(debug=True)时引发“app.run：[Errno 9]坏文件描述符”
提问于 2017-03-08 20:55:34
这仅仅是使用烧瓶调试过程的一部分吗？这是因为Flask服务器正在读取它正在写入的文件吗？我没有正确地关闭连接吗？
从我能收集到的 errno(9)指示：
(坏的文件号)，当您使用的文件描述符无效时。文件描述符不是指未打开的文件，就是对只为写入(或读取)打开的文件发出读(或写)请求。如果您正在进行套接字编程，则套接字描述符在对其进行任何操作之前已经关闭，并且可能会导致此错误。
我正在使用Virtualenv 15.1.0、Python3.6.0和Flask 0.12 &
$ pip freeze
appdirs==1.4.2
click==6.7
Flask==0.12
itsdangerous==0.24
Jinja2==2.9.5
MarkupSafe==0.23
packaging==16.8
pyparsing==2.1.10
requests==2.13.0
six==1.10.0
Werkzeug==0.11.15这是我正在编写的代码，它在退出服务器时调用错误：
from flask import Flask, render_template, request, jsonify
import sqlite3
app = Flask(__name__)
connection = sqlite3.connect('database.db')
connection.execute('CREATE TABLE IF NOT EXISTS films (title TEXT, rating INTEGER)')
connection.close() <------------------ IMPROPER CLOSURE?
@app.route('/')
def index():
return render_template("base.html")
@app.route('/movie', methods = ['POST'])
def add_movie_function():
connection = sqlite3.connect('database.db')
cursor = connection.cursor()
title = request.form['title']
rating = request.form['rating']
try:
query = 'INSERT INTO films (title, rating) VALUES (?, ?)'
cursor.execute(query, (title, rating))
connection.commit()
message = 'Successfully inserted title and rating data into movies table!'
except:
connection.rollback()
message = 'There was an issue with inserting data into the movies table :('
finally:
connection.close() <------------------ IMPROPER CLOSURE?
return message
@app.route('/movies', methods = ['GET'])
def list_all_movies():
connection = sqlite3.connect('database.db')
cursor = connection.cursor()
try:
cursor.execute('SELECT * FROM films')
connection.commit()
search_result = jsonify(cursor.fetchall())
except:
search_result = 'An error occured getting all the film titles'
finally:
connection.close() <------------------ IMPROPER CLOSURE?
return search_result
app.run(debug = True)...and这是完整的回溯：
(venv) 66 Wed Mar 08 15:29:11$ export FLASK_APP=simpleFlaskAPI.py
(venv) 67 Wed Mar 08 15:42:08$ flask run
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
* Debugger pin code: 230-157-201
127.0.0.1 - - [08/Mar/2017 15:42:21] "GET /movies HTTP/1.1" 200 -
^C * Serving Flask app "simpleFlaskAPI"
Traceback (most recent call last):
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/bin/flask", line 11, in <module>
sys.exit(main())
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/flask/cli.py", line 507, in main
cli.main(args=args, prog_name=name)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/flask/cli.py", line 374, in main
return AppGroup.main(self, *args, **kwargs)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/decorators.py", line 64, in new_func
return ctx.invoke(f, obj, *args[1:], **kwargs)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/flask/cli.py", line 432, in run_command
use_debugger=debugger, threaded=with_threads)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/werkzeug/serving.py", line 708, in run_simple
inner()
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/werkzeug/serving.py", line 670, in inner
fd=fd)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/werkzeug/serving.py", line 564, in make_server
passthrough_errors, ssl_context, fd=fd)
File "/Users/username/python/lesson4/python-minicamp-homework-4/venv/lib/python3.6/site-packages/werkzeug/serving.py", line 474, in __init__
socket.SOCK_STREAM)
File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socket.py", line 460, in fromfd
nfd = dup(fd)
OSError: [Errno 9] Bad file descriptor如果这是不正常的，我应该向烧瓶的人提交一份错误报告吗？
谢谢!
更新Pipskweak的建议，我修改了脚本：
from flask import Flask, render_template, request, jsonify
import sqlite3
app = Flask(__name__)
connection = sqlite3.connect('database.db')
connection.execute('CREATE TABLE IF NOT EXISTS films (title TEXT, rating INTEGER)')
connection.close()
@app.route('/')
def index():
return render_template("base.html")
@app.route('/movie', methods = ['POST'])
def add_movie_function():
data = None
try:
connection = sqlite3.connect('database.db')
with connection:
cursor = connection.cursor()
title = request.form['title']
rating = request.form['rating']
query = 'INSERT INTO films (title, rating) VALUES (?, ?)'
data = cursor.execute(query, (title, rating))
connection.commit()
message = 'Successfully inserted title and rating data into movies table!'
except sqlite3.Error as e:
if connection:
connection.rollback()
message = 'There was an issue with inserting data into the movies table :('
raise ValueError('sqlite3: {}'.format(e))
finally:
if connection:
connection.close()
print(message)
if data:
print(data)
return message
@app.route('/movies', methods = ['GET'])
def list_all_movies():
data = None
try:
connection = sqlite3.connect('database.db')
with connection:
cursor = connection.cursor()
data = cursor.execute('SELECT * FROM films')
connection.commit()
search_result = jsonify(cursor.fetchall())
except sqlite3.Error as e:
if connection:
search_result = 'An error occured getting all the film titles'
raise ValueError('sqlite3: {}'.format(e))
finally:
if connection:
connection.close()
print(search_result)
if data:
print(data)
return search_result
app.run(debug = True)
# if __name__ == '__main__':
# print('__name__ == "__main__"')
# app.run(debug = True)注意:使用if __name_ == ...不会在export FLASK_APP...和flask run调用烧瓶时调用调试器模式。然而，将python3 scriptname.py与if name == main一起使用是否会调用调试器--所以我怀疑这里的烧瓶有什么问题吗？
我还调整了脚本，使其在python 2中运行(只有一对打印语句和except sqlite3.Error, e:语法)，并尝试使用虚拟环境在Flask (使用调试器模式)中运行它，python脚本可以很好地处理html，当我退出Flask服务器时，没有OSError: Errno 9坏文件描述符。所以，这是我应该向酒瓶的人报告的错误吗？
FWIW：
$ pip freeze
appdirs==1.4.3
click==6.7
Flask==0.12
itsdangerous==0.24
Jinja2==2.9.5
MarkupSafe==1.0
packaging==16.8
pyparsing==2.2.0
requests==2.13.0
six==1.10.0
Werkzeug==0.11.15回答 1
Stack Overflow用户
发布于 2017-03-09 01:25:45
因此，try、except、finally语句可能会导致一些问题。
你想试试这个吗？对于异常和关闭连接，它会更具体一些。
def query_db(sql_statement):
try:
# connect to database
conn = sqlite3.connect('database.db')
with conn:
cur = conn.cursor()
data = cur.execute(sql_statement)
# commit the changes
conn.commit()
except sqlite3.Error, e:
# if an error has occured, rollback the changes
if conn:
conn.rollback()
# print the error out. Probably useful.
raise ValueError('sqlite3: {}'.format(e))
finally:
# lastly, close the database, probably a good idea.
if conn:
conn.close()
if data:
return data另外，您在if之前缺少了app.run()语句
if __name__ == "__main__":
app.run(debug=True)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/42681764
复制相关文章
相似问题
腾讯云开发者
Copyright © 2013 - 2026 Tencent Cloud. All Rights Reserved. 腾讯云 版权所有
深圳市腾讯计算机系统有限公司 ICP备案/许可证号：粤B2-20090059 
粤公网安备44030502008569号
腾讯云计算（北京）有限责任公司 京ICP证150476号 | 京ICP备11018762号