Flask 路由相關操做

時間 2019-11-10

標籤 flask 路由相關欄目 Python 简体版

原文原文鏈接

URL Route

URL 後接 / 做爲目錄級訪問
URL 後不接 / 做爲文件級訪問

from flask import Flask
app = Flask(__name__)

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

@app.route('/about')
def about():
    return 'The about page'

	說明
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

可使用methods來指定該路由使用的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()

參考

route

URL Binding

使用url_for()方法能夠調用參數中的route方法，以便知足某種調用目的，如單元測試。css

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'))

靜態文件伺候

靜態文件指應用使用的Javascript、CSS代碼及圖片資源文件。html

url_for('static', filename='style.css')

模板文件伺候

Flask會自動尋找templates目錄，因此原則上請不要自定義這個目錄的名字，且應該將其放在項目（或模塊）的根路徑下。python

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>

參考

請求處理

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)

參考

文件上傳

保存時從新指定文件名

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')
    ...

保存時，使用上傳的文件名

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))
    ...

參考

Uploading Files

Cookies

讀取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.

寫入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來找到URL地址
使用redirect來重定向

from flask import abort, redirect, url_for

@app.route('/')
def index():
    return redirect(url_for('login'))

使用abort來返回錯誤碼

@app.route('/login')
def login():
    abort(401)
    this_is_never_executed()

使用@app.errorhandler()來處理錯誤碼對應的請求

from flask import render_template

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

參考

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