标签: except

下面是我的表的简化版本.

    FRID, RELFRID, Relationship
    123, 456, Husband/Wife
    456, 123, Wife/Husband
    345, 765, Brother/Sister
    765, 345, Sister/Brother

我想只拉一个关系的表示(只是每组两个记录中的一个).我尝试了很多东西,包括EXCEPT和SUBSELECTS,我尝试的所有东西都没有结果,因为左边的每个数字也表示在右边.知道如何获得我正在寻找的结果吗？我已经尝试了以下查询的每个组合.

    select frid, relfrid from frrelmst
    except
    select frid, relfrid from frrelmst
    where frid in (select relfrid from frrelmst)
    order by frid, relfrid

    Select frid, relfrid from frrelmst where 
    relfrid+frid not in (select frid+relfrid from frrelmst)

Python 3.3中除了字符串的ValueError之外还有一种方法吗？如果我在k中键入一个字符串,我想要打印"无法将字符串转换为浮点数",而不是"不能取负数的平方根".

while True:
    try:
        k = float(input("Number? "))

....

    except ValueError:
        print ("Cannot take the square root of a negative number")
        break
    except ValueError:
        print ("Could not convert string to float")
        break

我试图理解Enumerable.Except方法的两个重载之间的区别,即

• 除外(IEnumerable,IEnumerable)
• 除外(IEnumerable,IEnumerable,IEqualityComparer)

显然,第一个不同之处在于第一个重载使用默认的相等比较器,而另一个使用IEqualityComparer,但我可以通过实现IEquatable接口(如MSDN文档中提到的Except方法)实现与第一个方法相同的结果,然后为什么需要第二次过载？

我试图检查用户输入的字符串的长度,如果它<5,它会通过但无论它的长度如何仍然通过我的尝试除了声明

打印"""请在公司的股票代码中加入您希望看到的最后收盘价格.""

while True:
   symbol = raw_input("Enter Stock Symbol: ")
   try:
      len(symbol) < 5
      break

   except ValueError:
      print 'Greater than 4 characters, Try again'

print 'Great your stock symbol is less than 5'

请原谅我这个令人困惑的头衔.但我无法想出更简单的东西.

我下了课.

public class Foo
{
    public FooId int { get; set; }

    public FooField string { get; set; }

    //some more fields here....
    //....
    //....

    public DateTime CreatedDate { get; set; }
}

我需要遍历的东西,并添加了一系列Foo的List<Foo>,但它不应该被重复的基础上的组合FooId和FooField.

所以我想尝试如下

List<Foo> foos = new List<Foo>();

foreach (Bar item in blah.Bars)
{
    //Some code here to get the foos from the item
    List<Foo> processedFoos = item.GetFoos();

    //The problem is with below line
    foos.AddRange(processedFoos.Except(foos));
}

该Except中心将所有的记录和复制的 …

我想知道python中是否有"all"的关键字except.我遇到了这个看似简单的问题:

try:
    #do stuff
except any as error:
    print('error: {err}'.format(err=error))

我知道您可以except:捕获所有错误,但我不知道如何添加as关键字来获取一个有print能力的对象.我想捕获任何错误,并能够获得一个用于打印或其他东西的对象.

I am looking for MySQL equivalent or equivalents for the following query:

(select course_id
from section
where semester = 'Fall' and year= 2009)
except
(select course_id
from section
where semester = 'Spring' and year= 2010);

where the section table is:

+-----------+--------+----------+------+----------+-------------+--------------+
| course_id | sec_id | semester | year | building | room_number | time_slot_id |
+-----------+--------+----------+------+----------+-------------+--------------+
| BIO-101   | 1      | Summer   | 2009 | Painter  | 514         | B            |
| BIO-301   | 1      | Summer   | 2010 …

如何STRUCT在不按名称指定的情况下自动应用于表中的所有字段？

不起作用的示例：

WITH data as (
 SELECT 'Alex' as name, 14 as age, 'something else 1' other_field
UNION ALL 
 SELECT 'Bert' as name, 14 as age, 'something else 2' other_field
UNION ALL 
 SELECT 'Chiara' as name, 13 as age, 'something else 3' other_field
)

SELECT AS STRUCT(SELECT * except (other_field) from data) as student_data

返回： Error: Scalar subquery cannot have more than one column unless using SELECT AS STRUCT to build STRUCT values at [9:17]

然而，这有效：

WITH data …

我有两个数组,我需要显示array1没有的数组,反之亦然.

string[] a = { "hello", "momo" }
string[] b = { "hello"}

输出:

momo

我正在使用.Except并尝试在消息框中显示输出,但是当我执行我的代码时,输​​出是这样的:

System.Linq.Enumerable+<ExceptIterator>d_99'1[System.Char]

我的代码:

//Array holding answers to test
string[] testAnswer = new string[20] { "B", "D", "A", "A", "C", "A", "B", "A", "C", "D", "B", "C", "D", "A", "D", "C", "C", "B", "D", "A" };
string a = Convert.ToString(testAnswer);

//Reads text file line by line. Stores in array, each line of the file is an element in the array
string[] inputAnswer = System.IO.File.ReadAllLines(@"C:\Users\Momo\Desktop\UNI\Software tech\test.txt");
string …

这是我脚本的一部分:

try:    
    read2length = len(reads[1])
    x2 = data[read1length:read1length+read2length,0]
    y2 = data[read1length:read1length+read2length,1]
    fig = plt.figure()
    plt.bar(x2,y2, align='center')
    fig.suptitle('Read 2 Camera Timeouts', fontsize=20)
    plt.xlabel('Cycle', fontsize=18)
    plt.ylabel('#', fontsize=16)
    if read2length < 50:
        plt.xticks(x1, fontsize=14)
    fig.savefig(join((path),'Read 2 Camera Timeouts.jpg'))
except: pass 
try:
    read3length = len(reads[2])
    x3 = data[read1length+read2length:read1length+read2length+read3length,0]
    y3 = data[read1length+read2length:read1length+read2length+read3length,1]
    fig = plt.figure()    
    plt.bar(x3,y3, align='center')
    fig.suptitle('Read 3 Camera Timeouts', fontsize=20)
    plt.xlabel('Cycle', fontsize=18)
    plt.ylabel('#', fontsize=16)
    if read3length < 50:
        plt.xticks(x1, fontsize=14)
    fig.savefig(join((path),'Read 3 Camera Timeouts.jpg'))
except: pass          

我希望脚本尝试第一个和第二个.他们是否工作我希望脚本继续.

我一直得到read2length没有定义？

这是怎么回事？

我一直在创建一个对文件进行排序的程序，我需要尝试捕捉错误

这是代码：

    try: 
        shutil.move(path, directory)
    except OSError:
        print 'ERROR: File name already in use'
        quit()

但是当我尝试这个错误时：

    except OSError:
    ^
IndentationError: unexpected unindent

任何建议将不胜感激

与新的.NET 6,7等一样,我们有一个列表的Except类.

List<int> A = new List<int>();
List<int> B = new List<int>();
List<int> C = A.Except(B).ToList();

我的问题是,如何最好地进行同一类的字符串版本:

string A = "<div><p>One</p><p>Two</p></div>";
string B = "<div><p>One</p><p>Two</p><p>Three</p></div>";
string C = A.Except(B).ToString();

获得结果= <p>Three</p>

相反,我得到:

System.Linq.Enumerable+<ExceptIterator>d__73`1[System.Char]

我究竟做错了什么？

编辑:

只需使用最大字符串除最小字符串,反转数组顺序:

string C = B.Except(A);

和使用:尼克 new string(C.ToArray());给了我:

hr

使用反向后略有预期的结果.