python实现上传图片和裁剪图片的后台功能

# URL: /api/portrait/upload
# 上传头像
class ApiPortraitUploadHandler(BaseHandler):
    @login_required()
    def post(self):
        # 获取当前图片的名称
        imgN = self.get_argument('imgN')
        imgE = self.get_argument('imgE')
        imgFile = os.path.realpath(os.path.join(os.path.dirname(__file__),
            "../static/uploads/portrait/tmp",imgN)+imgE)
        if os.path.exists(imgFile):
            os.remove(imgFile)  #删除用户切换的大图片

        upload_dir = os.path.realpath(os.path.join(os.path.dirname(__file__),
            "../static/uploads/portrait/tmp"))
        random_name = str(uuid.uuid4())
        # input 名字一定是"fileupload"
        file_data = self.request.files["fileupload"][0]
        original_name = file_data['filename']
        extension = os.path.splitext(original_name)[1].lower()
        if extension not in ['.png','.jpg','.gif']:
            self.write({'code':'err',
                        'msg':u'只允许上传png,jpg,gif格式的图片，你上传的格式是: %s'%extension})
            return
        final_name = random_name + extension
        final_path = os.path.join(upload_dir,final_name)
        file_length = len(file_data['body'])
        output_file = open(final_path, 'w')
        output_file.write(file_data['body'])
        output_file.close()
        # relative_path = "%d/%s" % (self.current_user.id,final_name)

        relative_path = "/static/uploads/portrait/tmp/%s" % (final_name)
        result = {'name':random_name, 'ext':extension,'path':relative_path }

        # without this header IE non-drag/drop upload will fail
        self.set_header("Content-Type", "text/plain")

        djson = {'code':'ok','uploads':result}
        self.write(djson)

# URL: /api/portrait/save
# 保存头像
class ApiPortraitSaveHandler(BaseHandler):
    @login_required()
    def post(self):
        imgN = self.get_argument('imgN')
        imgE = self.get_argument('imgE')
        imgP = self.get_argument('imgP')
        imgT = int(self.get_argument('imgT'))
        imgL = int(self.get_argument('imgL'))
        imgW = int(self.get_argument('imgW'))
        imgH = int(self.get_argument('imgH'))
        imgP = os.path.realpath(os.path.join(os.path.dirname(__file__),
            '..')+imgP)
        imgNewN = imgN
        if imgNewN == 'touxiang':
        imgNewN = str(uuid.uuid4())
        im = Image.open(imgP) #打开图片句柄
        box = (imgL,imgT,(imgW+imgL),(imgH+imgT)) #设定裁剪区域
        region = im.crop(box)  #裁剪图片，并获取句柄region
        imgPSave = os.path.realpath(os.path.join(os.path.dirname(__file__),
            '..','static','uploads','portrait',imgNewN)+imgE)
        # remove picture
        if os.path.exists(imgP) and imgN != 'touxiang':
            os.remove(imgP)   #保存之前删除此图片的大图
        userInfo = json.loads(self.current_user.info)
        if userInfo.has_key('portrait'):
            imgPBefore = os.path.realpath(os.path.join(os.path.dirname(__file__),
                '..','static','uploads','portrait',userInfo['portrait']))
        if os.path.exists(imgPBefore) :
            os.remove(imgPBefore)   #保存之前删除用户之前用的图片

        region.save(imgPSave) #保存图片
        if not userInfo.has_key('portrait') or userInfo['portrait'] != (imgNewN+imgE):
            userInfo['portrait'] = imgNewN + imgE
            self.current_user.info = json.dumps(userInfo)
            self.db.commit()
        self.write({'code':'ok'})