小编CDs*_*ace的帖子

有没有办法获取类实例上存在的属性列表？

class new_class():
    def __init__(self, number):
        self.multi = int(number) * 2
        self.str = str(number)

a = new_class(2)
print(', '.join(a.SOMETHING))

期望的结果是将输出"multi,str".我希望这能看到脚本各个部分的当前属性.

我有这个代码,我怎么能让它接受所有典型的图像格式？PNG,JPEG,JPG,GIF？

这是我到目前为止所拥有的:

public void EncryptFile()
{            
    OpenFileDialog dialog = new OpenFileDialog();
    dialog.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
    dialog.InitialDirectory = @"C:\";
    dialog.Title = "Please select an image file to encrypt.";

    if (dialog.ShowDialog() == DialogResult.OK)
    {
        //Encrypt the selected file. I'll do this later. :)
    }             
}

请注意,过滤器设置为.txt文件.我可以改为PNG,但其他类型呢？

我有一个开发数据库,​​经常从Visual Studio数据库项目(通过TFS自动构建)重新部署.

有时当我运行我的构建时,我收到此错误:

ALTER DATABASE failed because a lock could not be placed on database 'MyDB'. Try again later.  
ALTER DATABASE statement failed.  
Cannot drop database "MyDB" because it is currently in use.  

我试过这个:

ALTER DATABASE MyDB SET RESTRICTED_USER WITH ROLLBACK IMMEDIATE

但我仍然无法删除数据库.(我的猜测是大多数开发人员都dbo可以访问.)

我可以手动运行SP_WHO并开始查杀连接,但我需要一种自动方式在自动构建中执行此操作.(虽然这次我的连接是我试图丢弃的数据库中唯一的连接.)

是否有一个脚本可以删除我的数据库,无论谁连接？

我有一个单元测试,我必须模拟一个返回bool类型的非虚方法

public class XmlCupboardAccess
{
    public bool IsDataEntityInXmlCupboard(string dataId,
                                          out string nameInCupboard,
                                          out string refTypeInCupboard,
                                          string nameTemplate = null)
    {
        return IsDataEntityInXmlCupboard(_theDb, dataId, out nameInCupboard, out refTypeInCupboard, nameTemplate);
    }
}

所以我有一个XmlCupboardAccess类的模拟对象,我试图在我的测试用例中为这个方法设置mock,如下所示

[TestMethod]
Public void Test()
{
    private string temp1;
    private string temp2;
    private Mock<XmlCupboardAccess> _xmlCupboardAccess = new Mock<XmlCupboardAccess>();
    _xmlCupboardAccess.Setup(x => x.IsDataEntityInXmlCupboard(It.IsAny<string>(), out temp1, out temp2, It.IsAny<string>())).Returns(false); 
    //exception is thrown by this line of code
}

但是这条线引发了异常

Invalid setup on a non-virtual (overridable in VB) member: 
x => x.IsDataEntityInXmlCupboard(It.IsAny<String>(), …

附:

if(element.hasClass("class"))

我可以检查一个类,但有一个简单的方法来检查"元素"是否有任何类？

我在用:

if(element.hasClass("class") || element.hasClass("class") ... )

这不是太糟糕,但我想的是:

if(element.hasClass("class", "class2")

遗憾的是,这不起作用.

有类似的东西吗？

我试图运行一个程序在Python代码中进行一些系统调用subprocess.call(),这会引发以下错误:

Traceback (most recent call last):
      File "<console>", line 1, in <module>
      File "/usr/lib/python2.7/subprocess.py", line 493, in call
      return Popen(*popenargs, **kwargs).wait()
      File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
errread, errwrite)
      File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
      raise child_exception
      OSError: [Errno 2] No such file or directory

我的实际Python代码如下:

url = "/media/videos/3cf02324-43e5-4996-bbdf-6377df448ae4.mp4"
real_path = "/home/chanceapp/webapps/chanceapp/chanceapp"+url
fake_crop_path = "/home/chanceapp/webapps/chanceapp/chanceapp/fake1"+url
fake_rotate_path = "/home/chanceapp/webapps/chanceapp.chanceapp/fake2"+url
crop = "ffmpeg -i %s -vf "%(real_path)+"crop=400:400:0:0 "+ "-strict -2 %s"%(fake_crop_path)
rotate = "ffmpeg -i %s -vf "%(fake_crop_path)+"transpose=1 "+"%s"%(fake_rotate_path)
move_rotated …

我有以下内容:

answers = Answer.objects.filter(id__in=[answer.id for answer in answer_set.answers.all()])

然后:

for i in range(len(answers)):
    # iterate through all existing QuestionAnswer objects
    for existing_question_answer in existing_question_answers:
        # if an answer is already associated, remove it from the
        # list of answers to save
        if answers[i].id == existing_question_answer.answer.id:
            answers.remove(answers[i])           # doesn't work
            existing_question_answers.remove(existing_question_answer)

我收到一个错误:

'QuerySet' object has no attribute 'remove'

我已经尝试了各种将QuerySet转换为标准集或列表.什么都行不通.

如何从QuerySet中删除一个项目,以便它不会从数据库中删除它,并且不会返回一个新的QuerySet(因为它在一个不起作用的循环中)？

我想知道如何使用Material的图标,因为这不起作用:

<material-icon icon = "/img/icons/ic_access_time_24px.svg"> </material-icon> 

我想作为icon属性的参数给出的路径存在问题.我想知道这个图标文件夹到底在哪里？

如何回滚失败的rails迁移？我希望这rake db:rollback会撤消失败的迁移,但不会,它会回滚先前的迁移(失败的迁移减去一次).而且rake db:migrate:down VERSION=myfailedmigration也不起作用.我已经碰到了几次,这非常令人沮丧.这是我为复制问题所做的简单测试:

class SimpleTest < ActiveRecord::Migration
  def self.up
    add_column :assets, :test, :integer
    # the following syntax error will cause the migration to fail
    add_column :asset, :test2, :integer
  end

  def self.down
    remove_column :assets, :test
    remove_column :assets, :test2
  end
end

结果:

==  SimpleTest: migrating =====================================================
-- add_column(:assets, :test, :integer)
   -> 0.0932s
-- add_column(:asset, :error)
rake aborted!
An error has occurred, all later migrations canceled:

wrong number of arguments (2 for 3)

好吧,让我们回滚:

$ rake db:rollback
== …

我有arr 类型的列array.

我需要获取行,其中arr列包含值s

这个查询:

SELECT * FROM table WHERE arr @> ARRAY['s']

给出错误:

错误:运算符不存在:字符变化[] @> text []

为什么不起作用？

ps我知道any()运算符,但为什么不@>工作？