小编co2*_*f2e的帖子

在生成模型,查看器或控制器之前,我已创建了一个迁移文件,如下所示

class Papaers < ActiveRecord::Migration
  def self.up
   create_table :papers do |t|
   t.integer :unit_id, :null=>false
   t.integer :document_id, :null=>false
   t.timestamps
 end
end

 def self.down
   drop_table :papers
 end
end

运行良好,它创建了表.但现在我想为这个表创建一个模型.有没有办法在rails中运行迁移文件后创建模型？我看不到模型中论文下生成的任何模型.

我创建了一个这样的自定义属性类

    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
    public class AMemento : Attribute
    {

        public void method(){
        try {

        }
        catch (Exception) {

        }}
    }

并且我计划在处理程序中使用此自定义属性来捕获发生的任何异常，如下所示

    [AMemento]
    [Authorize]
    public JsonResult GetWeatherData()
    {
         //// code here which throw an exception
    }

我想知道如何完成自定义属性类以捕获 GetWeatherData() 处理程序中抛出的异常。是否可以像在 python 中那样实现高阶函数？

我需要安装机器人框架。

我已经安装了 python 3.7、wxPython 和 robotsframework。需要安装robotframework-ride。在尝试时pip install robotframework-ride，出现错误pip._internal.exceptions.InstallationError: Command "python setup.py egg_info" failed with error code 1 in C:\Users\mani~1\AppData\Local\Temp\pip-install-ee73re19\robotframework-ride\。

附上详细日志以供参考。

pip install robotframework-ride

删除了构建跟踪器 'C:\Users\mani~1\AppData\Local\Temp\pip-req-tracker-vdskcs3j' 命令“python setup.py Egg_info”在 C:\Users\mani~1\ 中失败，错误代码为 1 AppData\Local\Temp\pip-install-ee73re19\robotframework-ride\ 异常信息：

    Traceback (most recent call last):
      File "c:\users\mani\appdata\local\programs\python\python37-32\lib\site-packages\pip\_internal\basecommand.py", line 141, in main
        status = self.run(options, args)
      File "c:\users\mani\appdata\local\programs\python\python37-32\lib\site-packages\pip\_internal\commands\install.py", line 299, in run
        resolver.resolve(requirement_set)
      File "c:\users\mani\appdata\local\programs\python\python37-32\lib\site-packages\pip\_internal\resolve.py", line 102, in resolve
        self._resolve_one(requirement_set, req)
      File "c:\users\mani\appdata\local\programs\python\python37-32\lib\site-packages\pip\_internal\resolve.py", line 256, in _resolve_one
        abstract_dist = self._get_abstract_dist_for(req_to_install)
      File "c:\users\mani\appdata\local\programs\python\python37-32\lib\site-packages\pip\_internal\resolve.py", line 209, …

在python中迭代堆栈的具体方法是什么.使用for循环就像迭代列表一样是最好的做法吗？

嗨,我已经下载了lua提取它并尝试制作它

sg1@kalanamith:~/lua-5.2.1$ make linux test

之后你得到这个错误

ar rcu liblua.a lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o     lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o     lzio.o lauxlib.o lbaselib.o lbitlib.o lcorolib.o ldblib.o liolib.o lmathlib.o loslib.o     lstrlib.o ltablib.o loadlib.o linit.o 
ranlib liblua.a
gcc -O2 -Wall -DLUA_COMPAT_ALL -DLUA_USE_LINUX    -c -o lua.o lua.c    
gcc -o lua   lua.o liblua.a -lm -Wl,-E -ldl -lreadline -lncurses 
/usr/bin/ld: cannot find -lncurses
collect2: ld returned 1 exit status
make[2]: *** [lua] Error 1
make[2]: Leaving directory …

我使用以下代码来格式化小数

return string.Format(CultureInfo.CreateSpecificCulture("nb-NO"), "{0:N3}", decVal);

如果decVal不包含小数,我不想显示小数点,但我想显示没有零的正确格式的数字,如何执行此操作？

我正在从 PolkadotJS 生成公钥，如下所示

    const keyring = new Keyring({ type: "sr25519" });
    const account = keyring.addFromUri("//Bob", { name: "Bob default" });
    
    // encoded public key 
    let public_key = keyring.encodeAddress(account.publicKey, 42);
    console.log(public_key);

public_key我正在添加as的类型"public_key": "Vec<u8>",

我正在从 Substrate Node 读取公钥，如下所示

// pk_raw is a Vec<u8> array 
let pk =  str::from_utf8(pk_raw.as_ref()).unwrap() 
// the above returns `5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty`

我需要根据这个值生成公钥。我尝试了以下方法

ed25519::Public::try_from(&*pk_raw).unwrap(); 
// above throws error since the data length is not equals to 32

fn try_from(data: &[u8]) -> Result<Self, Self::Error> {
        if data.len() == 32 { …

根据下表，如何更新用户所在的组？我觉得我必须丢失一些显而易见的东西，但是到目前为止，我还没有发现任何显示该操作方法的东西。

group_permission_table = Table('group_permission', metadata,
    Column('group_name', Integer, ForeignKey('group.group_name', onupdate="CASCADE", ondelete="CASCADE")),
    Column('permission_name', Integer, ForeignKey('permission.permission_name', onupdate="CASCADE", ondelete="CASCADE"))
)

user_group_table = Table('user_group', metadata,
    Column('user_name', Integer, ForeignKey('user.user_name', onupdate="CASCADE", ondelete="CASCADE")),
    Column('group', Integer, ForeignKey('group.group_name', onupdate="CASCADE", ondelete="CASCADE"))
)

class Group(Base):
    """An ultra-simple group definition.
    """
    __tablename__ = 'group'

    group_name = Column("group_name", Text(), primary_key=True)

    users = relationship('User', secondary=user_group_table, backref='groups')

class User(Base):
    """Reasonably basic User definition. Probably would want additional
    attributes.
    """
    __tablename__ = 'user'

    user_name = Column("user_name", Text(), primary_key=True)
    _password = Column('password', Text)
    email = Column('email', Text())

有人吗 …

require 'simplecov'
require 'simplecov-rcov'

包括

SimpleCov.start 'rails'

在spec_helper.rb类中运行rpec/spec.但在运行之后,当我导航到0.0.0.0:3000/coverage/index.html时,我收到此错误

路由错误

没有路线匹配[GET]"/coverage/index.html"

这里可能出现什么问题？先感谢您.

我在Ubuntu 12.04上安装了python-dev,libglu-dev和libevent-dev软件包,但是当我尝试从sudo python setup.py install安装kivy时,它会抛出以下错误.

      Error compiling Cython file:
     -----------------------------------------------------------
   .    ..
          glDeleteFramebuffers(len(self.lr_fbo_fb), arr.data.as_uints)
         del self.lr_fbo_fb[:]
     if len(self.lr_fbo_rb):
         Logger.trace('Context: releasing %d renderbuffer fbos' % len(self.lr_fbo_fb))
         arr = self.lr_fbo_rb
         glDeleteRenderbuffers(len(self.lr_fbo_rb), arr.data.as_uints)
                                                           ^

 kivy/graphics/context.pyx:303:63: Cannot convert Python object to 'GLuint *'
building 'kivy.graphics.context' extension
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes     -fPIC -I/usr/include/python2.7 -c kivy/graphics/context.c -o build/temp.linux-x86_64-2.7   /kivy/graphics/context.o
 kivy/graphics/context.c:1:2: error: #error Do not use this file, it is the result    of       failed Cython compilation.

如果任何人能给我做什么,我将非常高兴.我尝试了一切.先感谢您.