Flask 路由相关操作

URL Route

  • URL 后接 / 作为目录级访问
  • URL 后不接 / 作为文件级访问
from flask import Flask
app = Flask(__name__)

@app.route('/')
def index():
    return 'Index Page'

@app.route('/about')
def about():
    return 'The about page'
type:XXX 说明
string (default) accepts any text without a slash
int accepts positive integers
float accepts positive floating point values
path like string but also accepts slashes
uuid accepts UUID strings 
from flask import Flask
app = Flask(__name__)

@app.route('/user/<username>')
def show_user_profile(username):
    # show the user profile for that user
    return 'User %s' % username
    
@app.route('/post/<int:post_id>')
def show_post(post_id):
    # show the post with the given id, the id is an integer
    return 'Post %d' % post_id
    
@app.route('/path/<path:subpath>')
def show_subpath(subpath):
    # show the subpath after /path/
    return 'Subpath %s' % subpath
  • 可以使用methods来指定该路由使用的HTTP方法。
from flask import request

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        return do_the_login()
    else:
        return show_the_login_form()

参考

URL Binding

使用url_for()方法可以调用参数中的route方法，以便满足某种调用目的，如单元测试。

from flask import Flask
from flask import Flask, url_for
app = Flask(__name__)

with app.test_request_context():
    print(url_for('index'))
    print(url_for('login'))
    print(url_for('login', next='/'))
    print(url_for('profile', username='John Doe'))

静态文件伺候

静态文件指应用使用的Javascript、CSS代码及图片资源文件。

  • 在项目根目录下创建static目录
url_for('static', filename='style.css')

模板文件伺候

Flask会自动寻找templates目录，所以原则上请不要自定义这个目录的名字，且应该将其放在项目（或模块）的根路径下。

from flask import Flask
from flask import render_template
app = Flask(__name__)

@app.route('/hello/')
@app.route('/hello/<name>')
def hello(name=None):
    return render_template('hello.html', name=name)

<body>
    Hello, World!

    from templates
</body>

参考

请求处理

Request

@app.route('/test', methods=['POST', 'GET'])
def test():
    error = None
    
    if request.method == 'POST':
        t1 = request.form['1']
        t2 = request.form['2']
    elif request.method == 'GET':
        # for URL `?key=value`
        t3 = request.args.get('key', '')
    else:
        error = 'Method is not POST or GET!'

    return render_template('test.html', error=error)

参考

文件上传

  • 保存时重新指定文件名
from flask import request

@app.route('/upload', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        f = request.files['the_file']
        f.save('/var/www/uploads/uploaded_file.txt')
    ...
  • 保存时，使用上传的文件名
from flask import request
from werkzeug.utils import secure_filename

@app.route('/upload', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        f = request.files['the_file']
        f.save('/var/www/uploads/' + secure_filename(f.filename))
    ...

参考

Cookies

  • 读取cookie
from flask import request

@app.route('/')
def index():
    username = request.cookies.get('username')
    # use cookies.get(key) instead of cookies[key] to not get a
    # KeyError if the cookie is missing.
  • 写入cookie
from flask import make_response

@app.route('/')
def index():
    resp = make_response(render_template(...))
    resp.set_cookie('username', 'the username')
    return resp

重定向

  • 使用url_for来找到URL地址
  • 使用redirect来重定向
from flask import abort, redirect, url_for

@app.route('/')
def index():
    return redirect(url_for('login'))
  • 使用abort来返回错误码
@app.route('/login')
def login():
    abort(401)
    this_is_never_executed()
  • 使用@app.errorhandler()来处理错误码对应的请求
from flask import render_template

@app.errorhandler(404)
def page_not_found(error):
    return render_template('page_not_found.html'), 404

参考

posted @ 2018-06-01 15:36  莫不逢  阅读(796)  评论(0)  编辑  收藏  举报