python - 为什么我的应用程序为每个新输入输出相同的结果？

Question

我正在创建一个使用鸢尾花数据集预测鸢尾花种类的应用程序。我正在使用 Flask 构建应用程序。我为应用程序提供了不同的输入，但与我的 kaggle 模型相比，我得到了不同的结果。我相信我的代码的机器学习部分没有任何问题，因为我已经在 Kaggle 上执行了它，并且不同的输入会导致不同的预测输出。在将机器学习与 HTML 集成后，我似乎不明白发生了什么以及为什么输出没有改变。由于我是 Flask 的初学者，如果解释保持简单，将不胜感激。

```
from flask import Flask, render_template, url_for, request, redirect
import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.neighbors import KNeighborsClassifier
from sklearn import metrics
from forms import InputForm
from io import StringIO
import pickle


app = Flask(__name__)
app.config['SECRET_KEY'] = '0dfd576186d78d2318e8c2987d56ec42'

@app.route('/')
def home():
    form = InputForm()
    return render_template('home.html', form=form)


@app.route('/predict', methods=['GET', 'POST'])
def predict():  
    icd = pd.read_csv("F:\Alekhya\Projects\IrisProject\data\irisdata.csv")
    features = ['sepal_length_cm', 'sepal_width_cm', 'petal_length_cm', 'petal_width_cm']
    X = icd[features]
    y = icd['class']
    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42, stratify=y)
    knn = KNeighborsClassifier(n_neighbors=7)
    knn.fit(X_train,y_train)
    pickle.dump(knn, open('model.pkl','wb'))
    model = pickle.load(open('model.pkl', 'rb'))

    if request.method == 'POST':
        pl = request.form['pl']
        sl = request.form['sl']
        pw = request.form['pw']
        sw = request.form['sw']
        df = pd.DataFrame({'sepal_length_cm': [sl], 'sepal_width_cm': [sw], 'petal_length_cm':[pl], 'petal_width_cm':[pw]})
        prediction = model.predict(df)
        return render_template('prediction.html', prediction=prediction[0])

这是我的 Home.html

{% extends "layout.html" %}
{% block content %} 

    <div class="content-section">
        <form method="POST" action="{{ url_for('predict') }}">
            {{ form.hidden_tag() }}
            <fieldset class="form-group">
                <legend class="border-bottom mb-4">Type the measurements in cm</legend>
                <div class="form-group">
                    {{ form.Petal_length.label(class="form-control-label") }}

                    {% if form.Petal_length.errors %}
                        {{ form.Petal_length(class="form-control form-control-lg is-invalid") }}
                        <div class="invalid-feedback">
                            {% for error in form.Petal_length.errors %}
                                <span>{{ error }}</span>
                            {% endfor %}
                        </div>
                    {% else %}
                        <input name="pl" class="form-control form-control-lg" type="text"></input>
                    {% endif %}
                </div>

                <div class="form-group">
                    {{ form.Sepal_length.label(class="form-control-label") }}

                    {% if form.Sepal_length.errors %}
                        {{ form.Sepal_length(class="form-control form-control-lg is-invalid") }}
                        <div class="invalid-feedback">
                            {% for error in form.Sepal_length.errors %}
                                <span>{{ error }}</span>
                            {% endfor %}
                        </div>
                    {% else %}
                        <input name="sl" class="form-control form-control-lg" type="text"v></input>
                    {% endif %}
                </div>

                <div class="form-group">
                    {{ form.Petal_width.label(class="form-control-label") }}

                    {% if form.Petal_width.errors %}
                        {{ form.Petal_width(class="form-control form-control-lg is-invalid") }}
                        <div class="invalid-feedback">
                            {% for error in form.Petal_width.errors %}
                                <span>{{ error }}</span>
                            {% endfor %}
                        </div>
                    {% else %}
                        <input name="pw" class="form-control form-control-lg" type="text"></input>
                    {% endif %}
                </div>

                <div class="form-group">
                    {{ form.Sepal_width.label(class="form-control-label") }}

                    {% if form.Sepal_width.errors %}
                        {{ form.Sepal_width(class="form-control form-control-lg is-invalid") }}
                        <div class="invalid-feedback">
                            {% for error in form.Sepal_width.errors %}
                                <span>{{ error }}</span>
                            {% endfor %}
                        </div>
                    {% else %}
                        <input name="sw" class="form-control form-control-lg" type="text"></input>
                    {% endif %}
                </div>
            </fieldset>
            <div class="form-group">
                {{ form.submit(class="btn btn-outline-info") }}
            </div>
        </form>
        <div class="p-3 mb-2 bg-dark text-white">
            {{ prediction }}
        </div>
        </div>

{% endblock content %}

这是我的 prediction.html

{% extends "layout.html" %}
{% block content %} 

    <div class="content-section">
        <div class="form-group">
            <div class="p-3 mb-2 bg-dark text-white">
                {{ prediction }}
            </div>
        </div>
        <div class="form-group">
            <button class="btn btn-outline-info"><a href={{ url_for('home') }}>Go Back</a></button>
        </div>
    </div>

{% endblock content %}

标签： pythonflaskscikit-learn