烧瓶jinja2.exceptions.UndefinedError：'？'未定义

Question

我是新来的，自己在做项目。我为此而苦苦挣扎，我无法弄清问题所在。我坚持下去，需要一些帮助。

这是我的route.py

ps -ax

这是我的模板文件夹中的return.html

@app.route("/", methods=["POST","GET"])
def main():         

    if request.method=="POST":
        name = request.form.get('name')
        amount = request.form.get('amount')
        day = request.form.get('daySelect')
        month = request.form.get('monthSelect')            
        year = request.form.get('yearSelect')

        months=["Ocak","Şubat","Mart","Nisan","Mayıs","Haziran","Temmuz","Ağustos","Eylül","Ekim","Kasım","Aralık"]
        date = "{}-{}-{}".format(year,month,day)
        day=int(day)
        month=int(month)-1
        year=int(year)
        try:  

            result = Action(name,date,amount)                      
            iname = result.TickerName()
            buy_price = result.Buy_Price()  
            sell_price = result.Sell_Price()
            today_amount = result.Today_Money(buy_price,sell_price)
            return render_template("return.html" , months=months, day=day, year=year, month=month ,name=name, amount=amount, iname=iname, result = result, buy_price = buy_price, sell_price = sell_price, today_amount=today_amount) 

        except:           

            return render_template("main.html")


    return render_template("main.html")

这是模板文件夹中的main.html

  {% extends "layout.html" %}




{% block form %}            

<form id="formdiv"  method="post" autocomplete="off" > 


    <div class="inputs"><label for="name">Hisse</label> </label> <input type='text' name='name' id='name' class="form-control" placeholder="AMZN,TSLA,NVDA,APPL..." value={{stock}}> </div>                        
    <div class="inputs"> <label for="amount">Miktar </label> <input type='text' name='amount' id='amount' class="form-control" placeholder="100,5000,600..." value={{amount}}> </div>
    <div class="inputs"> <label for="amount">Tarih </label> 
            <div id="dateid">
                <select class="form-control col-3" id="daySelect" name="daySelect" >
                    {% for i in range(1,32)  %}
                        <option value=i>{{i}}</option>
                    {% endfor %}

                </select>
                <select class="form-control col-3" id="monthSelect" name="monthSelect">           

                    {% for i in range(0,12)  %}
                        {% if i != month %}
                            <option value={{i+1}}>{{months[i]}}</option>

                        {% else %}
                            <option selected value={{i+1}}>{{months[i]}}</option>
                        {% endif %}

                    {% endfor %}



                </select>

                <select class="form-control col-3" id="yearSelect" name="yearSelect"> 
                    {% for i in range(1881,2021) %}      

                        {% if i==1919 %}
                            <option selected value=i>{{i}}</option>                                       
                        {% else %}
                            <option value=i>{{i}}</option> 
                        {% endif %}                                   
                    {% endfor %}

                </select> 
            </div>    
    </div>

    <button type="submit" class="btn btn-dark">HESAPLA</button>      
</form>
{% endblock form %}

我收到此错误

{% extends "layout.html" %}




    {% block form %}            

        <form id="formdiv" method="post"  autocomplete="off" > 


            <div class="inputs"><label for="name">Hisse</label> </label> <input type='text' name='name' id='name' class="form-control" placeholder="AMZN,TSLA,NVDA,APPL..."> </div>                        
            <div class="inputs"> <label for="amount">Miktar </label> <input type='text' name='amount' id='amount' class="form-control" placeholder="100,5000,600..."> </div>
            <div class="inputs"> <label for="amount">Tarih </label> 
                    <div id="dateid">
                        <select class="form-control col-3" id="daySelect" name="daySelect" >
                            {% for i in range(1,32)  %}
                                {% if i==19 %}
                                    <option selected value=i>{{i}}</option>                                        
                                {% else %}
                                    <option value=i>{{i}}</option>
                                {% endif %}     

                            {% endfor %}


                        </select>


                        <select class="form-control col-3" id="monthSelect" name="monthSelect">                                    
                            <option value=1>Ocak</option>
                            <option value=2>Şubat</option>
                            <option value=3>Mart</option>
                            <option value=4>Nisan</option>                            
                            <option value=5>Mayıs</option>        
                            <option value=6>Haziran</option>
                            <option value=7>Temmuz</option>
                            <option value=8>Ağustos</option>
                            <option value=9>Eylül</option>
                            <option value=10>Ekim</option>
                            <option value=11>Kasım</option>
                            <option value=12>Aralık</option>


                        </select>

                        <select class="form-control col-3" id="yearSelect" name="yearSelect"> 
                            {% for i in range(1881,2021) %}      

                                {% if i==1919 %}
                                    <option selected value=i>{{i}}</option>                                       
                                {% else %}
                                    <option value=i>{{i}}</option> 
                                {% endif %}                                   
                            {% endfor %}

                        </select> 
                    </div>    
            </div>

            <button type="submit" class="btn btn-dark">HESAPLA</button>      
        </form>
    {% endblock form %}

文件“ C：\ Users \ Egemen \ Desktop \ Stock \ stock \ templates \ main.html”，第27行，在块“窗体”中 {{months [i]}}

这样说，但是在main.html中，第27行没有此代码