打开pycharm新建一个flask项目,如果你想省事可以参考一下截图,新建项目:
找到app.py点击鼠标右键运行:
运行成功:
访问这个地址即可!
from flask import Flask, current_app
app = Flask(__name__,
static_url_path="/python", # 访问静态资源的url前缀, 默认值是static
static_folder="static", # 静态文件的目录,默认就是static
template_folder="templates", # 模板文件的目录,默认是templates
)
#使用对象配置参数
class Config(object):
DEBUG = True
FLY = "fly"
app.config.from_object(Config)
@app.route("/")
def index():
# 读取配置参数
# 1. 直接从全局对象app的config字典中取值
# print(app.config.get("ITCAST"))
# 2. 通过current_app获取参数
print(current_app.config.get("FLY"))
return "hello flask"
if __name__ == '__main__':
# 启动flask程序
app.run(host="0.0.0.0", port=5000, debug=True)
from flask import Flask, request
import json
app = Flask(__name__)
@app.route("/index", methods=["GET", "POST"])
def index():
"""获取表单数据"""
name = request.form.get("name")
age = request.form.get("age")
return {'ret':0,'msg':name+age}
@app.route("/index2", methods=["GET", "POST"])
def index2():
"""获取json数据"""
str_json = request.data
return {'ret':0,'msg':json.loads(str_json)}
@app.route("/index", methods=["GET", "POST"])
def index():
"""获取args数据"""
city = request.args.get("city")
return {'ret':0,'msg':city}
if __name__ == '__main__':
app.run(debug=True)
测试代码
import requests,pprint
def post():
data = {
'name': 'fly2',
'age': 18
}
# response = requests.post('http://127.0.0.1:5000/index1',data=data)
json = {
'city':'beijing',
'weather':'-15'
}
# response = requests.post('http://127.0.0.1:5000/index2',json=json)
args = {
'city':'beijing'
}
response = requests.post('http://127.0.0.1:5000/index3', params=args)
pprint.pprint(response.json())
if __name__ == '__main__':
post()
from flask import Flask, request
app = Flask(__name__)
@app.route("/upload", methods=["POST"])
def upload():
"""接受前端传送过来的文件"""
file_obj = request.files.get("pic")
if file_obj is None:
# 表示没有发送文件
return "未上传文件"
# 直接使用上传的文件对象保存
file_obj.save("./demo1.png")
return "上传成功"
if __name__ == '__main__':
app.run(debug=True)
如果在视图函数执行过程中,出现了异常错误,我们可以使用abort函数立即终止视图函数的执行。
from flask import Flask, request, abort, Response
app = Flask(__name__)
@app.route("/login", methods=["POST"])
def login():
"""获取表单数据"""
name = request.form.get("name")
pwd = request.form.get("pwd")
if name != "zhangsan" or pwd != "admin":
# 使用abort函数可以立即终止视图函数的执行
# 并可以返回给前端特定的信息
# 1 传递状态码信息, 必须是标准的http状态码
abort(404)
# # 2. 传递响应体信息
# resp = Response("login failed")
# abort(resp)
return "login success"
# 定义错误处理的方法
@app.errorhandler(404)
def handle_404_error(err):
"""自定义的处理错误方法"""
return "出现了404错误, 错误信息:%s" % err
if __name__ == '__main__':
app.run(debug=True)
from flask import Flask, request, abort, Response, make_response
app = Flask(__name__)
@app.route("/index")
def index():
# 1 使用元祖,返回自定义的响应信息
# 响应体 状态码 响应头
# return "index page", 400, [("Fly", "pyton"), ("City", "shenzhen")]
# return "index page", 400, {"Fly": "python1", "City1": "sz1"}
# 2 使用make_response 来构造响应信息
resp = make_response("index page 2")
resp.status = "999 itcast" # 设置状态码
resp.headers["city"] = "sz" # 设置响应头
return resp
if __name__ == '__main__':
app.run(debug=True)
from flask import Flask
from werkzeug.routing import BaseConverter
class Regex_url(BaseConverter):
def __init__(self,url_map,*args):
super(Regex_url,self).__init__(url_map)
self.regex = args[0]
app = Flask(__name__)
app.url_map.converters['re'] = Regex_url
@app.route('/user/' )
def hello_itcast(id):
return 'hello %s' %id
from flask import Flask, jsonify
app = Flask(__name__)
@app.route("/index")
def index():
return jsonify(city="sz", country="china")
if __name__ == '__main__':
app.run(debug=True)
from flask import Flask, make_response, request
app = Flask(__name__)
@app.route("/set_cookie")
def set_cookie():
resp = make_response("success")
# 设置cookie, 默认有效期是临时cookie,浏览器关闭就失效
resp.set_cookie("Fly", "Python")
resp.set_cookie("Fly1", "Python1")
# max_age设置有效期,单位:秒
resp.set_cookie("Fly2", "Python1", max_age=3600)
resp.headers["Set-Cookie"] = "Fly3=Python3; Expires=Sat, 18-Nov-2017 04:36:04 GMT; Max-Age=3600; Path=/"
return resp
@app.route("/get_cookie")
def get_cookie():
c = request.cookies.get("Fly")
return c
@app.route("/delete_cookie")
def delete_cookie():
resp = make_response("del success")
# 删除cookie
resp.delete_cookie("Fly")
return resp
if __name__ == '__main__':
app.run(debug=True)
from flask import Flask, session, current_app
app = Flask(__name__)
# flask的session需要用到的秘钥字符串
app.config["SECRET_KEY"] = "dhsodfhisfhosdhf29fy989"
@app.route("/login")
def login():
# 设置session数据
session["name"] = "python"
session["mobile"] = "18611111111"
return "login success"
@app.route("/index")
def index():
# 获取session数据
name = session.get("name")
return "hello %s" % name
if __name__ == '__main__':
app.run(debug=True)
在客户端和服务器交互的过程中,有些准备工作或扫尾工作需要处理,比如:在请求开始时,建立数据库连接;在请求结束时,指定数据的交互格式。为了让每个视图函数避免编写重复功能的代码,Flask提供了通用设施的功能,即请求钩子。
from flask import Flask, request, url_for
app = Flask(__name__)
@app.route("/index")
def index():
print("index 被执行")
return "index page"
@app.route("/hello")
def hello():
print("hello 被执行")
return "hello page"
@app.before_first_request
def handle_before_first_request():
"""在第一次请求处理之前先被执行"""
print("handle_before_first_request 被执行")
@app.before_request
def handle_before_request():
"""在每次请求之前都被执行"""
print("handle_before_request 被执行")
@app.after_request
def handle_after_request(response):
"""在每次请求(视图函数处理)之后都被执行, 前提是视图函数没有出现异常"""
print("handle_after_request 被执行")
return response
@app.teardown_request
def handle_teardown_request(response):
"""在每次请求 (视图函数处理)之后都被执行, 无论视图函数是否出现异常,都被执行, 工作在非调试模式时 debug=False"""
print("handle_teardown_request 被执行")
return response
if __name__ == '__main__':
app.run()
通过使用Flask-Script扩展,我们可以在Flask服务器启动的时候,通过命令行的方式传入参数。
from flask import Flask
from flask_script import Manager # 启动命令的管理类
app = Flask(__name__)
# 创建Manager管理类的对象
manager = Manager(app)
@app.route("/index")
def index():
return "index page"
if __name__ == '__main__':
# app.run(debug=True)
# 通过管理对象来启动flask
manager.run()
结束!!!