【pythonflask-1】简单实现加减乘除输入界面

news2024/12/23 8:15:51

app.py

import flask
from flask import Flask, render_template, request
# 计算精确的浮点结果，float加法也计算不出来
from decimal import Decimal

app = Flask(__name__)

@app.route('/')
def home():
    return render_template('index.html')

@app.route('/calculate', methods=['POST'])
# POST请求处理用户提交的数据
def calculate():
    num1 = Decimal(request.form['num1'])
    num2 = Decimal(request.form['num2'])
    operation = request.form['operation']
    result = Decimal(0)
    # 输入的两个数和运算符，结果初始为0

    if operation == 'add':
        result = num1 + num2
        # 加
    elif operation == 'subtract':
        result = num1 - num2
        # 减
    elif operation == 'multiply':
        result = num1 * num2
        # 乘
    elif operation == 'divide':
        if num2 != Decimal(0):
            result = num1 / num2
        else:
            return "错误:分母不能为0"
        # 除
    result = round(result,4)
    # 保留四位小数

    return render_template('result.html', num1=num1, num2=num2, operation=operation, result=result)
    # 然后将计算结果和输入的两个参数返回给result.html渲染
if __name__ == '__main__':
    app.run(debug=True)

templates文件夹

index.html

<!DOCTYPE html>
<html>
<head>
    <title>在线计算器</title>
</head>
<body>
    <h1>在线计算器</h1>
    <form action="/calculate" method="POST">
        <!-- 获得请求 -->
        <input type="text" name="num1" required>
        <select name="operation" required>
            <option value="add">+</option>
            <option value="subtract">-</option>
            <option value="multiply">*</option>
            <option value="divide">/</option>
            <!-- 加减乘除的操作 -->
        </select>
        <input type="text" name="num2" required>
        <button type="submit">开始计算</button>
        <!-- 提交表单 -->
    </form>
</body>
</html>
<!-- type="number" 时，浏览器会为输入字段提供一些额外的验证和用户界面上的增强功能，
例如限制输入为数值、显示数值调节器控件等。 -->

result.html

<!DOCTYPE html>
<html>
<head>
    <title>计算结果</title>
</head>
<body>
    <h1>计算结果</h1>
    <p>{{ num1 }} {{ operation }} {{ num2 }} = {{ result }}</p>
    <!-- 执行相关的计算操作的变量 -->
</body>
</html>