上传 Flask 中的图像并将其存储在本地文件夹中

Question

我想上传一个图像并将其传递给 flask 中的 python 代码，以便它可以在本地存储和调用图像。 从教程中我有这段代码，但是查询似乎有问题，请求总是以“无文件部分”结尾：

if 'file' not in request.files:
    flash('No file part')
    return redirect(request.url)

如果我检查请求中包含哪些数据：

print(request.data)
print(request.args)
print(request.form) 

这给了我以下结果：

b''
ImmutableMultiDict([])
ImmutableMultiDict([('file', '6b6e63084d829d765f318a123f9997d6.jpg')])

这是我的 python 代码

ALLOWED_IMAGE_TYPES = set(["png", "jpg", "jpeg", "gif"])

def allowed_file(filename):
    print("Check if image types is allowed")
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_IMAGE_TYPES


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

    if request.method == "POST":
        if 'file' not in request.files:
            flash('No file part')
            return redirect(request.url)
        file = request.files['file']
        if file.filename == '':
            flash('No image selected for uploading')
            return redirect(request.url)
        if file and allowed_file(file.filename):
            print("test2")
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            print('upload_image filename: ' + filename)
            flash('Image successfully uploaded and displayed below')
            return render_template('index.html', filename=filename)
        else:
            flash('Allowed image types are - png, jpg, jpeg, gif')
            return redirect(request.url)

    else:
        return render_template("crop.html")

@app.route('/display/<filename>')
def display_image(filename):
    print('display_image filename: ' + filename)
    return redirect(url_for('static', filename='uploads/' + filename), code=301)

<div class="container">
<div class="row">
<p>
    {% with messages = get_flashed_messages() %}
      {% if messages %}
        <ul>
        {% for message in messages %}
          <li>{{ message }}</li>
        {% endfor %}
        </ul>
      {% endif %}
    {% endwith %}
</p>
{% if filename %}
    <div>
        <img src="{{ url_for('display_image', filename=filename) }}">
    </div>
{% endif %}
<form method="POST" action="/crop" enctype="multipart/form-data">
    <dl>
        <p>
            <input type="file" name="file" value="file" id="file" class="form-control" autocomplete="off" required>
        </p>
    </dl>
    <p>
        <input type="submit" value="Submit" class="btn btn-info">
    </p>
</form>

Answer 1

request.files是一个字典 object，因此检查名称是否在其中应该可以工作。 由于某种原因它不是，所以你可以尝试检查它是否在keys()中，尽管这应该是不必要的。

if 'file' not in request.files.keys():
    flash('No file part')
    return redirect(request.url)

Answer 2

在HTML代码中发现问题，大括号两边的引号是错误的。

 <img src={{ url_for('display_image', filename=filename) }}>