Python Flask 教程 - 404 Not Found
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Flask tutorial - 404 Not Found
提问by
I just finished the Flask basic tutorial (here) and even though I've done completed every step, when I am trying
我刚刚完成了 Flask 基础教程（这里），即使我已经完成了每一步，当我尝试
python flaskr.py
python flaskr.py
what I get is a 404 Not Founderror saying
我得到的是一个404 Not Found错误说
The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
here is the code inside the file
这是文件中的代码
import os
import sqlite3
from flask import Flask, request, session, g, redirect, url_for, abort, render_template, flash
#create app
app = Flask(__name__)
app.config.from_object(__name__)
#load default conf and override config from an env var
app.config.update(dict(
DATABASE=os.path.join(app.root_path, 'flaskr.db'),
DEBUG=True,
SECRET_KEY = 'dev key',
USERNAME = 'admin',
PASSWORD = 'admin'
))
app.config.from_envvar('FLASKR_SETTINGS', silent=True)
def connect_db():
"""connect to the specific db"""
rv = sqlite3.connect(app.config['DATABASE'])
rv.row_factory = sqlite3.Row
return rv
if __name__== '__main__':
app.run()
def get_db():
"""opens a new db connection if there is none yet for the cyrrent app"""
if not hasattr(g, 'sqlite_db'):
g.sqlite_db = connect_db()
return g.sqlite_db
@app.teardown_appcontext
def close_db(error):
"""closes the db again at the end of the request."""
if hasattr(g, 'sqlite_db'):
g.sqlite_db.close()
def init_db():
with app.app_context():
db = get_db()
with app.open_resource('schema.sql', mode='r') as f:
db.cursor().executescript(f.read())
db.commit()
@app.route('/')
def show_entries():
db_get_db()
cur = db.execute('select title, text from entries order by id desc')
entries = cur.fetchall()
return render_template('show_entries.html', entries=entries)
@app.route('/add', methods=['POST'])
def add_entry():
if not session.get('logged_in'):
abort(401)
db = get_db()
db.execute('insert into entries (title, text) values (?,?)',
[request.form['title'], request.form['text']])
db.commit()
flash('New entry was successfully posted')
return redirect(url_for('show_entries'))
@app.route('/login', methods=['GET', 'POST'])
def login():
error = None
if request.method == 'POST':
if request.form['username'] != app.config['USERNAME']:
error = 'Invalid username'
elif request.form['password'] != app.config['PASSWORD']:
error = 'Invalid password'
else:
session['logged_in'] = True
flash('You were logged in')
return redirect(url_for('show_entries'))
return render_template('login.html', error=error)
@app.route('/logout')
def logout():
session.pop('logged_in', None)
flash('You were logged out')
return redirect(url_for('show_entries'))
This is the console message I get (plus 3 attempts to refresh page):
这是我得到的控制台消息（加上 3 次刷新页面的尝试）：
user@user:~/Flask/flaskr$ python flaskr.py
* Running on http://127.0.0.1:5000/
* Restarting with reloader
127.0.0.1 - - [19/Aug/2014 15:23:40] "GET / HTTP/1.1" 404 -
127.0.0.1 - - [19/Aug/2014 15:23:41] "GET / HTTP/1.1" 404 -
127.0.0.1 - - [19/Aug/2014 15:23:42] "GET / HTTP/1.1" 404 -
Any suggestions on what might be going wrong?
关于可能出什么问题的任何建议？
采纳答案by Martijn Pieters
You put your app.run()call too early:
你太早app.run()打电话了：
if __name__== '__main__':
app.run()
This is executed before any of your routes are registered. Move these two lines to the endof your file.
这是在注册任何路由之前执行的。将这两行移到文件的末尾。
Next, you have the first line in show_entries()is incorrect:
接下来，您输入的第一行show_entries()不正确：
def show_entries():
db_get_db()
There is no db_get_db()function; this should be db = get_db()instead.
没有db_get_db()功能；这应该是db = get_db()。
回答by Salman Haseeb Sheikh
Happened to me also while following Flask Application Setup here. The error was gone after appending a trailing slash at the end of the route.
在此处遵循 Flask 应用程序设置时也发生在我身上。在路径末尾附加斜杠后，错误消失了。
@app.route('/hello')
def hello():
return 'Hello, World!'
was changed to
改为
@app.route('/hello/')
def hello():
return 'Hello, World!'
and the problem was solved. Hope it helps for anyone who is searching for a problem like this.
问题就解决了。希望它对任何正在寻找此类问题的人有所帮助。
