如何在Flask中处理输入字段的特定用户错误

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1 回答

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数据工程师

提问于 2025-04-13 13:45

我正在为我的爬虫程序做一个网站。在这个网站上，我有三个输入框（第二个是可选的）。如果用户在第一个或第三个输入框里什么都不填，就会出现这样的提示信息：

当你输入了城市名称，但没有填最后一个输入框时，最后一个输入框也会出现同样的提示信息。

我想限制用户在最后一个输入框里只能输入“wohnung”或“haus”。我写了一段代码来实现这个功能，但它没有正常工作。如果用户在这个输入框里输入了其他内容，就会显示爬虫已经开始的提示，如下图所示：

所以，如果用户输入的内容不是上面提到的那两个词，我希望它能显示得像什么都没写一样。

处理输入框的功能代码如下：

def run_scraper(city, subregion, apart_or_house):
    # Ask the user for input
    base_url = ""
    while True:
        if city != "":
            break
        else:
            flash("City name cannot be empty. Please enter a valid city name.", "error")
            return

    while True:
        if apart_or_house == "wohnung" or apart_or_house == 'haus':
            break
        elif apart_or_house == "":
            flash("This field cannot be empty. Please enter what are you buying.", "error")
        else:
            flash("Please enter either 'wohnung' or 'haus'.", "error")
            return

    if subregion:
        base_url = f"https://www.immobilienscout24.de/Suche/de/{city}/{city}/{subregion}/{apart_or_house}-kaufen"
    else:
        base_url = f"https://www.immobilienscout24.de/Suche/de/{city}/{city}/{apart_or_house}-kaufen"

    #Run the scraper script with the provided inputs and base_url
    subprocess.run(['python', 'scraper.py', city, subregion, apart_or_house, base_url])
    session['scraping_finished'] = True
    flash('Scraper has finished!', 'info')
    g.scraping_finished = True

而调用这个功能的路由代码如下：

@app.route('/scrape', methods=['GET', 'POST'])
def scrape():
    form = ScrapingForm()
    if form.validate_on_submit():
        city = request.form.get('city')
        subregion = request.form.get('subregion')
        apart_or_house = request.form.get('apart_or_house')

        if city and apart_or_house:
            g.scraping_finished = False
            threading.Thread(target=run_scraper, args=(city, subregion, apart_or_house)).start()
            flash('Scraping started!', 'success')
        else:
            flash('Please fill all required fields.', 'error')

    if g.get('scraping_finished', False):
        flash('Scraper has finished!', 'info')

    return render_template('scrape.html', form=form)

表单处理用户输入验证 flask 爬虫程序错误提示输入框限制路由配置选项字段

1 个回答

如果你想在公寓和房子之间做个选择，可以用你的表单来限制这个选择。这样就不需要后续再进行验证了。

from flask_wtf import FlaskForm
from wtforms import StringField, SelectField
from wtforms.validators import DataRequired, Optional
from wtforms.widgets import CheckboxInput

class ScrapingForm(FlaskForm):
    city = StringField('City', 
        validators=[DataRequired()]
    )
    subregion = StringField('Subregion', 
        validators=[Optional()]
    )
    apart_or_house = SelectField('Buying', 
        choices=[('wohnung', 'Apartment'), ('haus', 'House')], 
    )

@app.route('/scrape', methods=['GET', 'POST'])
def scrape():
    form = ScrapingForm(request.form)
    if form.validate_on_submit():
        city = form.city.data
        subregion = form.subregion.data 
        apart_or_house = form.apart_or_house.data
        threading.Thread(target=run_scraper, args=(city, subregion, apart_or_house)).start()
        # ...
    return render_template('scrape.html', **locals())

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title></title>
</head>
<body>
    <form method="POST">
        {{ form.hidden_tag() }}
        <div>
            {{ form.city.label() }}
            {{ form.city() }}
            {% if form.city.errors -%}
                <ul>
                    {% for error in form.city.errors -%}
                    <li>{{ error }}</li>
                    {% endfor -%}
                </ul>
            {% endif -%}
        </div>
        <div>
            {{ form.subregion.label() }}
            {{ form.subregion() }}
            {% if form.subregion.errors -%}
                <ul>
                    {% for error in form.subregion.errors -%}
                    <li>{{ error }}</li>
                    {% endfor -%}
                </ul>
            {% endif -%}
        </div>
        <div>
            {{ form.apart_or_house.label() }}
            {{ form.apart_or_house() }}
            {% if form.apart_or_house.errors -%}
                <ul>
                    {% for error in form.apart_or_house.errors -%}
                    <li>{{ error }}</li>
                    {% endfor -%}
                </ul>
            {% endif -%}
        </div>
        <button type="submit">Submit</button>
    </form>
</body>
</html>

回答于 2025-04-13 由 Python大师

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如何在Flask中处理输入字段的特定用户错误

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