1.一個簡單的應用
#app.py
from flask import Flask
app = Flask('__name__')
@app.route('/')
def home():
return 'hello world'
if __name__ == '__main__':
app.run()
命令行執行 python app.py
瀏覽器輸入：http://localhost:5000/
simpleapp.png
2.跳轉到靜態html
#app.py
from flask import Flask
app = Flask('__name__', static_url_path='')
@app.route('/')
def home():
return app.send_static_file('view/index.html')
@app.route('/sigin', methods=['GET'])
def singin():
return app.send_static_file('view/singin.html')
@app.route('/sigin', methods=['POST'])
def main():
return app.send_static_file('view/main.html')
if __name__ == '__main__':
app.run()
- static_url_path: 指定靜態文件路徑，默認文件夾名static
- app.send_static_file:發送靜態文件。
文件結構：
圖片.png
- index.html
<h1>Home</h1>
- singin.html
<html>
<form action="/sigin" method="post">
<p><input name="username"></p>
<p><input name="password"></p>
<p><button type="submit">Sign In</button></p>
</form>
</html>
- main.html
<h3>hello world</h3>
3.模板
-
做一個模板
默認情況下，模板會從templates路徑下加載。
圖片.png
模板內容大致如下：
<html>
<head>
<title>Error Page</title>
</head>
<body>
<p>Username ( {{ username }} )is error or password ({{pwd}}) is error</p>
</body>
</html>
- 使用這個模板
使用flask里面的render_template方法返回這個模板。具體代碼是把
之前那個app.py內容改成下面這樣：
from flask import Flask, request, render_template
app = Flask('__name__', static_url_path='')
@app.route('/')
def home():
return app.send_static_file('view/index.html')
@app.route('/sigin', methods=['GET'])
def singin():
return app.send_static_file('view/singin.html')
@app.route('/sigin', methods=['POST'])
def main():
name = request.form['username']
password = request.form['password']
if (name == 'user' and password == 'pwd'):
return app.send_static_file('view/main.html')
else:
return render_template('error.html', username=name, pwd=password)
if __name__ == '__main__':
app.run()
- render_template 函數
這個函數主要是邏輯是：
傳入數據和模板 組裝 ?組裝后數據send給前臺
def render_template(template_name_or_list, **context):
"""Renders a template from the template folder with the given
context.
:param template_name_or_list: the name of the template to be
rendered, or an iterable with template names
the first one existing will be rendered
:param context: the variables that should be available in the
context of the template.
"""
ctx = _app_ctx_stack.top
ctx.app.update_template_context(context)
return _render(ctx.app.jinja_env.get_or_select_template(template_name_or_list),
context, ctx.app)
def _render(template, context, app):
"""Renders the template and fires the signal"""
before_render_template.send(app, template=template, context=context)
rv = template.render(context)
template_rendered.send(app, template=template, context=context)
return rv
參考
flask官網： http://flask.pocoo.org/docs/0.12/quickstart/#a-minimal-application
廖雪峰Python：https://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/001432012745805707cb9f00a484d968c72dbb7cfc90b91000
