小编sau*_*atz的帖子

我正在尝试使用setuptools在Ubuntu 14.04上安装PyOpenCV.当我尝试

python setup.py config 

我收到了错误

ImportError: cannot import name Library

我在上一个问题的答案中发现修复是要改变的

from setuptools import Library  

至

from setuptools.extension import Library

在setup.py中.现在,当我运行setup.py时,错误发生在它生成的config.py脚本中:

$ python setup.py config
Configuring PyOpenCV via CMake...
<snip>
-- Configuring done
-- Generating done
-- Build files have been written to:  /home/saul/Downloads/pyopencv/build
Traceback (most recent call last):
File "setup.py", line 137, in <module>
import config as C
File "/home/saul/Downloads/pyopencv/config.py", line 1, in <module>
from setuptools import Extension, Library
ImportError: cannot import name Library

config.py的第一行包含相同的导入错误.我当然可以更正config.py,但我不知道如何恢复构建过程.

从失败点出发的setup.py文本是:

    import config …

我试图在Monad.Reader问题8中理解Brent Yorgey的多集分区算法.自从我写了任何Haskell以来已经有很长一段时间了,我想我甚至忘记了基本的东西.我坚持这个清单中的代码:

我应该告诉你,这Vec是一个类型别名[Int],这<|=意味着向量的分量比较:

该函数withinFromTo应该返回非负矢量分量地的名单<= m,以及按字典之间s以及e(含).

我被困在线上:

[x:xs | x <- [start, (start-1)..end] 

什么[start, (start-1)..end]意思？我去了tryhaskell.org尝试评估,[3,2..7]但它只是给了我[].

我知道这看起来像是一个愚蠢的问题,但我无法通过谷歌搜索找到任何东西,而且我觉得我可以在浏览文档之前阅读文档很长时间.

谢谢你的帮助.

我正在尝试构建一个程序,其源代码是我从互联网上下载的.当我尝试编译它时,我收到错误消息

friend declaration specifying a default argument must be the only declaration

这是违规代码:

typedef int Var;
struct Lit {
    int     x;
    // Use this as a constructor:
    friend Lit mkLit(Var var, bool sign = false);
    bool operator == (Lit p) const { return x == p.x; }
    bool operator != (Lit p) const { return x != p.x; }
    bool operator <  (Lit p) const { return x < p.x;  } 
inline  Lit  mkLit(Var var, bool sign) { …

Here's a snippet of code where I get a syntax error I don't understand:

  let deal:[Card] = self.cards
       for hand in hands {
           var data:[Int] = []
           for card:Card in hand.cards {
               let idx = deal.indexOf(card) 
               data.append(idx!)
           }
       }

The error I get is "Cannot invoke 'indexOf' with an argument of type '(Card)'". I don't understand this at all. deal is an [Card]. What should I invoke deal.indexOf with if not a Card? The signature for CollectionType.indexOf in the docs …