Flask 实践1
2018-03-09 本文已影响0人
可爱喵星人
1.一个简单的应用
#app.py
from flask import Flask
app = Flask('__name__')
@app.route('/')
def home():
return 'hello world'
if __name__ == '__main__':
app.run()
命令行执行 python app.py
浏览器输入：http://localhost:5000/
simpleapp.png
2.跳转到静态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: 指定静态文件路径，默认文件夹名static
- app.send_static_file:发送静态文件。
文件结构：
图片.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
-
做一个模板
默认情况下，模板会从templates路径下加载。
图片.png
模板内容大致如下：
<html>
<head>
<title>Error Page</title>
</head>
<body>
<p>Username ( {{ username }} )is error or password ({{pwd}}) is error</p>
</body>
</html>
- 使用这个模板
使用flask里面的render_template方法返回这个模板。具体代码是把
之前那个app.py内容改成下面这样：
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 函数
这个函数主要是逻辑是：
传入数据和模板 组装 ⇒组装后数据send给前台
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
参考
flask官网： http://flask.pocoo.org/docs/0.12/quickstart/#a-minimal-application
廖雪峰Python：https://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/001432012745805707cb9f00a484d968c72dbb7cfc90b91000
