Flask 的常用模块和命令

本文最后更新于：June 1, 2023 9:58 PM

本健忘症晚期患者自用

模块

Basebones App

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from flask import Flask
app = Flask(__name__)

@app.route('/hello')
def hello():
	return 'Hello, World!'
	
if __name__ == '__main__':
	app.run(debug=True)

Routing

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@app.route('/hello/<string:name>, methods=['GET', 'POST'])
def hello(name): 
	return 'Hello ' + name + '!'

Templates

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return render_template('template_file.html', val1 = value1, ...)

JSON Responses

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import jsonify

@app.route('/returnstuff')
def returnstuff():
	num_list = [1,2,3,4,5]
	num_dict = {'numbers' : num_list, 'name' : 'Numbers'}
	#returns {'output' : {'numbers' : [1,2,3,4,5], 'name' : 'Numbers'}}
	return jsonify({'output' : num_dict})

Access Request Data

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request.args['name'] #query string arguments
request.form['name'] #form data
request.method #request type
request.cookies.get('cookie_name') #cookies
request.files['name'] #files

Redirect

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return redirect(url_for('index'))

命令

Create virtual environment locally

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virtualenv env

Activate virtual environment

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source env/Scripts/activate

Create database

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$ python
>>> from app import db
>>> db.create_all()

部署

用的 Heroku

Freeze requirements

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pip freeze > requirements.txt

Procile

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web: gunicorn app:app

Get postgresql

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heroku addons:create heroku-postgresql:hobby-dev --app [appname]

Get datatbase url

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heroku conig --app [appname]

Remember to change postgres://... to postgresql://...