我对 Flask 还是很陌生，更不用说 Python 了，我希望能够从 index.py 的下拉列表中获取数据并在我的 main.html 代码中为其分配一个变量。但是，当我运行程序时，我的 TOcurrency 值是空的。任何帮助表示赞赏。
main.html
<html lang="en">
<head>
<title>Exchange list</title>
</head>
<body>
<div class = 'Container'>
<form acion = '/' method = "POST" id = 'myform'>
<div class = "amount">
<input type="number" name = 'amount' value='0'>
</div>
<div class = 'drop-list'>
<div class = 'from' name = 'from_code'>From
<select>
{% for i in countries %}
<option value = {i}>{{i}}</option>
{% endfor %}
</select>
</div>
<div type = 'to' name = 'to_code'>To
<select>
{% for i in countries %}
<option value = {i}>{{i}}</option>
{% endfor %}
</select>
</div>
</div>
<div><input type = 'number' name = 'result'></div>
<button>Convert Currency</div>
</form>
</div>
</body>
</html>
index.py代码
from flask import Flask, render_template, request
import requests
import json
from api import *
app = Flask(__name__)
@app.route("/", methods = ['GET', 'POST'])
def home():
if request.method == 'POST':
amount = request.form['amount']
TOcurrency = request.form.getlist('to_code')
# FROMcurency = request.form['from_code']
print(amount,TOcurrency)
with open('exchange.json') as json_file:
data = json.load(json_file)
countryMap = data['conversion_rates']
countries = countryMap.keys()
print(countries)
return render_template('main.html', countries = countries)
if __name__ == "__main__":
app.run(debug=True)