在flask中提交資料時如何處理錯誤

當通過用戶輸入提交資料并且資料與 mongodb 集合中的任何內容都不匹配時，Jinja 模板會拋出錯誤（TypeError: 'NoneType' object is not subscriptable）但是當資料存在于集合中時，資料會加載到模板而沒有任何問題，我不知道如何處理這個錯誤。以及如何在提交后重繪 頁面，因為重新加載頁面后搜索輸入的結果不會消失。任何幫助將不勝感激，并提前致謝。

這是我的 Python 代碼：

import os
from datetime import datetime
from flask import (
    Flask, flash, render_template,
    redirect, request, session, url_for)
from flask_pymongo import PyMongo
from bson.objectid import ObjectId
from werkzeug.security import generate_password_hash, check_password_hash
if os.path.exists("env.py"):
    import env


app = Flask(__name__)


app.config["MONGO_DBNAME"] = os.environ.get("MONGO_DBNAME")
app.config["MONGO_URI"] = os.environ.get("MONGO_URI")
app.secret_key = os.environ.get("SECRET_KEY")


mongo = PyMongo(app)


@app.route("/")
@app.route("/home", methods=["GET", "POST"])
def home():
    return render_template("home.html")


@app.route("/search", methods=["GET", "POST"])
def search():
    query = request.form.get("company-name")
    company = mongo.db.company.find_one(
        {"company_name": query})["company_name"]
    if company:
        review = list(mongo.db.review.find({"company_name": company}))
    else:
        return redirect(url_for("home"))
    return render_template("home.html", review=review)

html Jinja 模板

    <form class="serach-form" method="POST" action="{{ url_for('search') }}">
        <label class="search-bar-label" name="company-name" for="company- 
              name">Company Name</label>
            <input type="text" id="company-name" name="company-name">
            <button class="serch-button btn light-blue accent-4" type="submit" 
              name="action"><span>Search</span>
                <i class="fas fa-sign-in-alt sign-in-icon"></i><i class="fas fa- 
              search search-icon"></i>
            </button>
    </form>

<div>
    {% if review|length > 0 %}
        {% for set in review %}
            <strong>{{ set.company_name }}</strong> <br>
            <strong>{{ set.username }}</strong><br>
            <strong>{{ set.score }}</strong><br>
            <strong>{{ set.review_content }}</strong><br>           
        {% endfor %} 
    {% else %}
        <h3 class="red-text text-darken-4 center-align">No Results Found</h3>
    {% endif %}       
        
</div>

uj5u.com熱心網友回復：

我找到了解決方案，但仍然不知道我寫的代碼有什么問題。

蟒蛇代碼

@app.route("/search", methods=["GET", "POST"])
def search():
    query = request.form.get("company-name")
    review = list(mongo.db.review.find(
        {"company_name": query}))
    return render_template("home.html", query=query, review=review)


html :
<div id="review-search">
{% if review|length > 0 %}
<h2 class="black-text text-darken-4 center-align review-search- 
     heading">Results for  <span class="found"> {{ query }} </span> 
</h2>
<h3> total {{ total_score }}</h3>

    {% for set in review %}
    <div class="row top-margin hot-company">
        <div class="col m8 s10 offset-m2 offset-s1 grey lighten-5">
            <div class="row">
                <div class="col s10 offset-s1 blue-text">
                    <h5>{{ set.username }}</h5>
                </div>
            </div>
            <div class="row">
                <div class="col s10 offset-s1 red-text">
                    <p>{{ set.score }}/10</p>
                </div>
            </div>
            <div class="row">
                <div class="col s10 offset-s1">
                    <p>{{ set.review_content }}</p>
                </div>
            </div>
        </div>
    </div>     
    {% endfor %}
{% else %}
    <h2 class="red-text text-darken-4 center-align review-search- 
         heading">No Results Found for   <span> "{{ query }}"</span> 
    </h2>
{% endif %}
</div>

uj5u.com熱心網友回復：

利用

try:
  // task1
except:
  // executed when there's runtime error while doing task1

標籤：Python MongoDB 烧瓶

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