用Flask上传图片和标签

3 投票
1 回答
6286 浏览
提问于 2025-04-20 18:57

我正在用Flask玩一个图片上传器。我是从这个仓库克隆的 https://github.com/chokepoint/flaskgur 。现在它在我的VPS上运行得很好。

http://107.170.119.38

我想做的是让用户在上传图片时可以写一个自定义标签。最终的效果应该是显示一张图片和用户输入的自定义标签。图片上传器运行得不错,但我似乎无法在上传时把标签存储到数据库里。以下是我的代码:

from flask import Flask, request, g, redirect, url_for, abort, render_template,send_from_directory
from werkzeug import secure_filename
from hashlib import md5
from PIL import Image
import sqlite3
import os
import time

DEBUG              = True
BASE_DIR           = '/var/www/flaskgur/'
UPLOAD_DIR         = BASE_DIR + 'pics'
DATABASE           = BASE_DIR + 'flaskgur.db'
ALLOWED_EXTENSIONS = set(['png', 'jpg', 'jpeg', 'gif'])

app = Flask(__name__)
app.config.from_object(__name__)

# Make sure extension is in the ALLOWD_EXTENSIONS set
def check_extension(extension):
    return extension in ALLOWED_EXTENSIONS

def connect_db():
    return sqlite3.connect(app.config['DATABASE'])

# Return a list of the last 25 uploaded images  
def get_last_pics():
    cur = g.db.execute('select * from pics order by id desc limit 25')
    filenames = [dict(id=row[0], filename=row[1], label=row[2]) for row in cur.fetchall()]
    #filenames = [row[0] for row in cur.fetchall()]
    return filenames

# Insert filename into database 
def add_pic(filename, label):
    g.db.executemany('insert into pics (filename, label) values (?, ?)', [filename, label])
    g.db.commit()

# Generate thumbnail image
def gen_thumbnail(filename):
    height = width = 200
    original = Image.open(os.path.join(app.config['UPLOAD_DIR'], filename))
    thumbnail = original.resize((width, height), Image.ANTIALIAS)
    thumbnail.save(os.path.join(app.config['UPLOAD_DIR'], 'thumb_'+filename))


def add_label(label):
    label = request.form['label']
    g.db.execute('INSERT INTO pics (label) VALUES (?)', [label])
    g.db.commit()


# Taken from flask example app
@app.before_request
def before_request():
    g.db = connect_db()

# Taken from flask example app
@app.teardown_request
def teardown_request(exception):
    db = getattr(g, 'db', None)
    if db is not None:
        db.close()

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@app.route('/', methods=['GET','POST'])
def upload_pic():
    if request.method == 'POST':
        file = request.files['file']
        try:
            extension = file.filename.rsplit('.', 1)[1].lower()
        except IndexError, e:
            abort(404)
        if file and check_extension(extension):
            # Salt and hash the file contents
            filename = md5(file.read() + str(round(time.time() * 1000))).hexdigest() + '.' + extension
            file.seek(0) # Move cursor back to beginning so we can write to disk
            file.save(os.path.join(app.config['UPLOAD_DIR'], filename, label))
            add_pic(filename)
            add_label(label)
            gen_thumbnail(filename)
            return redirect(url_for('show_pic', filename=filename))
        else: # Bad file extension
            abort(404)
    else:
        return render_template('upload.html', pics=get_last_pics())

@app.route('/show')
def show_pic():
    filename = request.args.get('filename','')
    return render_template('upload.html', filename=filename, label=label)
def show_label():
    g.db = connect_db()
    cur = g.db.execute('SELECT label FROM pics WHERE id=(?)')
    labels = cur.fetchone()
    return render_template('upload.html', labels=labels)

@app.route('/pics/<filename>')
def return_pic(filename):
    return send_from_directory(app.config['UPLOAD_DIR'], secure_filename(filename))

if __name__ == '__main__':
    app.run(debug=True,host='0.0.0.0')

还有我的模板(upload.html):

{% if filename is defined %}
    <div id="image"><a href="{{ pic_path(filename) }}" target="_blank"><img class="new" src="{{ pic_path(filename) }}"></a></div>

        <h2><p>The Label is: </p>{{ labels }}</h2>


{% else %}
    <ul>
    {% for pic in pics %}
        <li class="thumb"><a href="{{ url_for('show_pic', filename=pic) }}"><img class="thumb" src="{{ pic_path('thumb_'+pic) }}"></a></li>
    {% endfor %}

基础模板(base.html):

    <div id="upload">
        <h1>Upload Picture</h1>
        <form action="/" method=post enctype=multipart/form-data>
        <p>
            <input type=file name=file><br />
            <p>Add a Label:</p>
            <input type=text name=label value={{ request.form.label }}><br />
            <input type=submit value=Upload>
        </p>
    </div>

如果我的代码很糟糕,我很抱歉。我正在尽力学习。

1 个回答

2

我搞定了。把 get_last_pics() 这个函数重写成了这样:

# Return a list of the last 25 uploaded images
def get_last_pics():
try:
    cur = g.db.execute('select filename, label from pics order by id desc limit 25')
    filenames = []
    for row in cur.fetchall():
        filenames.append({"filename": row[0], "label": row[1] or ''})
    return filenames
except:
    return []

把 add_pic() 也重写成了这样:

# Insert filename and label into database
def add_pic(filename, label):
g.db.execute('insert into pics (filename, label) values (?, ?)', [filename, label])
g.db.commit()

把 upload_pic() 也重写成了这样:

@app.route('/', methods=['GET', 'POST'])
def upload_pic():
if request.method == 'POST':
    file = request.files['file']
    label = request.form['label']
    try:
        extension = file.filename.rsplit('.', 1)[1].lower()
    except IndexError, e:
        abort(404)
    if file and check_extension(extension):
        # Salt and hash the file contents
        filename = md5(file.read() + str(round(time.time() * 1000))).hexdigest() + '.' + extension
        file.seek(0)  # Move cursor back to beginning so we can write to disk
        file.save(os.path.join(app.config['UPLOAD_DIR'], filename))
        add_pic(filename, label)
        gen_thumbnail(filename)
        return redirect(url_for('show_pic', filename=filename))
    else:
        # Bad file extension
        abort(404)
else:
    return render_template('upload.html', pics=get_last_pics()) 

把 show_pic() 也重写成了这样:

@app.route('/show')
def show_pic():
filename = request.args.get('filename', '')
t = (filename,)
cur = g.db.execute('select label from pics where filename=?', t)
label = cur.fetchone()[0]

return render_template('upload.html', filename=filename, label=label)

现在一切都正常了。希望这能对将来的人有所帮助。

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