利用flask和前端进行数据交互

1. 字符交互

1.1. 导入库函数

from flask import Flask, render_template
from flask import Flask, redirect, url_for, request
app = Flask(__name__)

1.2. 定义函数

@app.route('/des_name/<name>/')
def des_name(name):
    return "%s"%name

@app.route('/')
def f():
    return render_template('login.html')

@app.route('/',methods = ['POST', 'GET'])
def login():
   if request.method == 'POST':
       user = request.form['nm']
       print(user)
       return redirect(url_for('des_name',name=user))
   else:
       user = request.args.get('nm')
       print(user)
       return redirect(url_for('des_name',name=user))

1.3. 调用

if __name__ == '__main__':
	app.run(debug = True)

2. 图片交互

2.1. 引入库函数

from flask import Flask
from flask import render_template, request
import base64
import os

2.2. 定义函数

def return_img_stream(img_local_path):
    """
    工具函数:
    获取本地图片流
    :param img_local_path:文件单张图片的本地绝对路径
    :return: 图片流
    """
    import base64
    img_stream = ''
    with open(img_local_path, 'rb') as img_f:
        img_stream = img_f.read()
        img_stream = base64.b64encode(img_stream).decode()
    return img_stream

# 获取项目当前绝对路径
# 比如我的项目在桌面上存放则得到——"C:\Users\asus\Desktop\shou"
basedir = "C:/Users/jimore/Documents/Tencent Files/3457822025/FileRecv/yolov5-master"

# 实例
app = Flask(__name__)


# 在根路由下返回上面的表单页面
@app.route('/', methods=['GET'])
def index():
    return render_template("dd.html")


# 表单提交路径，需要指定接受方式
@app.route('/getImg/', methods=['GET', 'POST'])
def getImg():
    # 通过表单中name值获取图片
    imgData = request.files["image"]
    # 设置图片要保存到的路径
    path = basedir + "/static/upload/img/"
    print(path)

    # 获取图片名称及后缀名
    imgName = imgData.filename

    # 图片path和名称组成图片的保存路径
    file_path = path + imgName

    # 保存图片
    imgData.save(file_path)

    img_stream = return_img_stream(file_path)
    return render_template('hh.html',
                           img_stream=img_stream)

2.3. 调用

app.run()