You should define `__nonzero__()` in Python 2.x.  It was only renamed to `__bool__()` in Python 3.x.  (The name `__nonzero__()` actually predates the introduction of the `bool` type by many years.)

I have a button that triggers a chain of events. One of these events is to **delete a sheet**. Before the user deletes anything, I pop up my custom YES/NO message asking them to confirm the whole process.

Then comes the sub event of deleting the sheet, and **Excel pops up its own window** for confirming the removal of the sheet. Problem is that if the user says &quot;no&quot; at that point, that sets my application in an inconsistent state.

How can I **bypass Excel asking to confirm the deletion** of a sheet ?


Delete Sheets and avoid Excel asking the user to confirm, using custom messages instead

Super quick question here that has been bugging me for a very long time -
Is there any way to remove the light bulb that appears on the left side of the line when there is a warning in Eclipse (Specifically using Java IDE, if it matters).

It is very annoying the way it hides breakpoints, and honestly - I can see the little squiggly yellow line just fine.

Thanks.

Eclipse - how to remove light bulb on warnings

&gt; **Possible Duplicate:**  
&gt; [defining &amp;ldquo;boolness&amp;rdquo; of a class in python](https://stackoverflow.com/questions/8205558/defining-boolness-of-a-class-in-python)  

&lt;!-- End of automatically inserted text --&gt;

I thought this should print &quot;False&quot;, why is it printing &quot;True&quot;?

    &gt;&gt;&gt; class Foo(object):
    ...   def __bool__(self):
    ...     return False
    ... 
    &gt;&gt;&gt; f = Foo()
    &gt;&gt;&gt; if f:
    ...   print &quot;True&quot;
    ... else:
    ...   print &quot;False&quot;
    ... 
    True
    &gt;&gt;&gt;



How to overload Python&#39;s __bool__ method?

> Possible Duplicate: 
> <a href="https://stackoverflow.com/questions/8205558/defining-boolness-of-a-class-in-python" target="_blank" rel="noopener noreferrer">defining “boolness” of a class in python</a>

I thought this should print "False", why is it printing "True"?
<pre><code class="hljs language-python-repl">>>> class Foo(object):
... def __bool__(self):
... return False
... 
>>> f = Foo()
>>> if f:
... print "True"
... else:
... print "False"
... 
True
>>>
</code></pre>

PIL does support JPEG in my system.

Whenever I do an upload, my code is failing with:

    File &quot;PIL/Image.py&quot;, line 375, in _getdecoder
        raise IOError(&quot;decoder %s not available&quot; % decoder_name)
    IOError: decoder jpeg not available

How can I resolve this?

Python Image Library fails with message &quot;decoder JPEG not available&quot; - PIL

I have to run a Python script on a Windows server. How can I know which version of Python I have, and does it even really matter?

I was thinking of updating to the latest version of Python.






Which version of Python do I have installed?

I have been reading the doc and searching but cannot seem to find a straight answer:

Can you cancel an already executing task? (as in the task has started, takes a while, and half way through it needs to be cancelled)

I found this from the doc at [Celery FAQ][1]

    &gt;&gt;&gt; result = add.apply_async(args=[2, 2], countdown=120)
    &gt;&gt;&gt; result.revoke()

But I am unclear if this will cancel queued tasks or if it will kill a running process on a worker.  Thanks for any light you can shed!



  [1]: http://docs.celeryproject.org/en/latest/faq.html#can-i-cancel-the-execution-of-a-task

Cancel an already executing task with Celery?

I created a virtualenv around my project, but when I try to activate it I cannot.
It might just be syntax or folder location, but I am stumped right now.

You can see below, I create the virtualenv and call it venv. Everything looks good, then I try to activate it by running `source venv/bin/activate`

I&#39;m thinking it might just have to do with my system path, but not sure what to point it to (I do know how to edit the path). I&#39;m on python 7 / windows os, virtual env 2.2.x

&lt;pre&gt;
Processing dependencies for virtualenv
Finished processing dependencies for virtualenv

c:\testdjangoproj\mysite&gt;virtualenv --no-site-packages venv
The --no-site-packages flag is deprecated; it is now the default behavior.
Using real prefix &#39;C:\\Program Files (x86)\\Python&#39;
New python executable in venv\Scripts\python.exe
File venv\Lib\distutils\distutils.cfg exists with different content; not overwri
ting
Installing setuptools.................done.
Installing pip...................done.

c:\testdjangoproj\mysite&gt;source venv/bin/activate
&#39;source&#39; is not recognized as an internal or external command,
operable program or batch file.

c:\testdjangoproj\mysite&gt;source venv/bin/activate
&#39;source&#39; is not recognized as an internal or external command,
operable program or batch file.

c:\testdjangoproj\mysite&gt;source mysite/bin/activate
&#39;source&#39; is not recognized as an internal or external command,
operable program or batch file.

c:\testdjangoproj\mysite&gt;
&lt;/pre&gt;


Issue with virtualenv - cannot activate

How do you trace the path of a Breadth-First Search, such that in the following example:

![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Breadth-first-tree.svg/300px-Breadth-first-tree.svg.png)

If searching for key `11`, return the **shortest** list connecting 1 to 11.

    [1, 4, 7, 11]

How to trace the path in a Breadth-First Search?

I&#39;m interested what&#39;s the reason to have call() method in JS. It seems it duplicates usual method of calling `this`.

For example, I have a code with call().

    var obj = {
    	objType: &quot;Dog&quot;
    }
    
    f = function(did_what, what) {
    	alert(this.objType + &quot; &quot; + did_what + &quot; &quot; + what);
    }
    
    f.call(obj, &quot;ate&quot;, &quot;food&quot;);

The output is &quot;Dog ate food&quot;. But the same result I can get assigning the function to the object.

    var obj = {
        objType: &quot;Dog&quot;
    }
        
    f = function(did_what, what) {
        alert(this.objType + &quot; &quot; + did_what + &quot; &quot; + what);
    }
    
    obj.a = f;
    obj.a(&quot;ate&quot;, &quot;food&quot;);

The result is the same. But this way is more understandable and convenient to use. Why call() is needed?

The reason to use JS .call() method?

I am fairly new to unit testing in C# and learning to use Moq. Below is the class that I am trying to test.

    class MyClass
    {
        SomeClass someClass;
        public MyClass(SomeClass someClass)
        {
            this.someClass = someClass; 	
        }

        public void MyMethod(string method)
        {
            method = &quot;test&quot;
            someClass.DoSomething(method);
        }	
    }

    class Someclass
    {
        public DoSomething(string method)
        {
            // do something...
        }
    }

Below is my TestClass:

    class MyClassTest
    {
        [TestMethod()]
        public void MyMethodTest()
        {
            string action=&quot;test&quot;;
            Mock&lt;SomeClass&gt; mockSomeClass = new Mock&lt;SomeClass&gt;();
            mockSomeClass.SetUp(a =&gt; a.DoSomething(action));
            MyClass myClass = new MyClass(mockSomeClass.Object);
            myClass.MyMethod(action);
            mockSomeClass.Verify(v =&gt; v.DoSomething(It.IsAny&lt;string&gt;()));
        }
    }

I get the following exception:

    Expected invocation on the mock at least once, but was never performed
    No setups configured.
    No invocations performed..

I just want to verify if the method &quot;MyMethod&quot; is being called or not. Am I missing something?


Verify a method call using Moq

I know that declaring a function (normal function not a method inside a class) as inline is a good practice when the function definition is small for performance and it save time for the compilation. But how about inline methods inside a class 
I don&#39;t understand the concept of inline methods inside a class? How to define them and how they work.

inline function members inside a class

I was wondering if it was possible to do a ternary operation but without returning anything.

If it&#39;s not possible in Java is it possible in other languages, if so which ones apply?



    
    name.isChecked() ? name.setChecked(true):name.setChecked(false);

Java: Ternary with no return. (For method calling)

    class MyClass:
    	def myFunc(self):
    		pass

Can I create `MyFunc()` outside of the class definition, maybe even in another module?


Define a method outside of class definition?

Related: https://stackoverflow.com/questions/7779013/probrem-with-constexpr-how-to-resolve-it

I feel like constexpr is limited in usefulness in C++11 because of the inability to define two functions that would otherwise have the same signature, but have one be constexpr and the other not constexpr. In other words, it would be very helpful if I could have, for example, a constexpr std::string constructor that takes constexpr arguments only, and a non-constexpr std::string constructor for non-constexpr arguments. Another example would be a theoretically complicated function that could be made more efficient by using state. You can&#39;t easily do that with a constexpr function, so you are left with two choices: have a constexpr function that is very slow if you pass in non-constexpr arguments, or give up on constexpr entirely (or write two separate functions, but you may not know which version to call).

My question, therefore, is this:

Is it possible for a standard-compliant C++11 implementation to allow function overloading based on the arguments being constexpr, or would this require updating the standard? If it is not allowed, was it intentionally not allowed?

--------------------

@NicolBolas: Say I have a function that maps an `enum` to a `std::string`. The most straight-forward way to do this, assuming my `enum` goes from `0` to `n - 1`, is to create an array of size `n` filled with the result.

I could create a `static constexpr char const * []` and construct a `std::string` on return (paying the cost of creating a `std::string` object every time I call the function), or I can create a `static std::string const []` and return the value I look up, paying the cost of all of the `std::string` constructors the first time I call the function. It seems like a better solution would be to create the `std::string` in memory at compile time (similar to what is done now with `char const *`), but the only way to do this would be to alert the constructor that it has `constexpr` arguments.

For a an example other than a `std::string` constructor, I think it&#39;s pretty straight-forward to find an example where, if you could ignore the requirements of `constexpr` (and thus create a non-`constexpr` function), you could create a more efficient function. Consider this thread: https://stackoverflow.com/questions/7065200/constexpr-question-why-do-these-two-different-programs-run-in-such-a-different

If I call `fib` with a `constexpr` argument, I can&#39;t beat do better than the compiler optimizing away the function call entirely. But if I call `fib` with a non-`constexpr` argument, I may want to have it call my own version that implements things like memoization (which would require state) so I get run time similar to what would have been my compile time had I passed a `constexpr` argument.

constexpr overloading

I read few questions here on SO about this topic which seems yet confusing to me. I&#39;ve just begun to learn C++ and I haven&#39;t studied templates yet or operator overloading and such.

Now is there a simple way to overload

    class My {
    public:
        int get(int);
        char get(int);
    }

without templates or strange behavior? or should I just 

    class My {
    public:
        int get_int(int);
        char get_char(int);
    }

?

Overloading by return type

I am trying to implement method overloading in Python: 

    class A:
        def stackoverflow(self):  	
            print &#39;first method&#39;
        def stackoverflow(self, i):
            print &#39;second method&#39;, i

    ob=A()
    ob.stackoverflow(2)

but the output is `second method 2`; similarly:

    class A:
        def stackoverflow(self):  	
            print &#39;first method&#39;
        def stackoverflow(self, i):
            print &#39;second method&#39;, i

    ob=A()
    ob.stackoverflow()

gives

    Traceback (most recent call last):
      File &quot;my.py&quot;, line 9, in &lt;module&gt;
        ob.stackoverflow()
    TypeError: stackoverflow() takes exactly 2 arguments (1 given)

How do I make this work?

How do I use method overloading in Python?

Assume that this is a `ServiceContract` 

    [ServiceContract]
    public interface MyService
    {
        [OperationContract]
        int Sum(int x, int y);

        [OperationContract]
        int Sum(double x, double y);

    }

Method overloading is allowed in C#, but WCF does not allow you to overload `operation contracts`
The hosting program will throw an `InvalidOperationException` while hosting

Why method overloading is not allowed in WCF?

I have the following class:

    class risc { // singleton
        protected:
            static unsigned long registers[8];
    
        public:
            unsigned long operator [](int i)
            {
                return registers[i];
            }
    };

as you can see I&#39;ve implemented the square brackets operator for &quot;getting&quot;.  
Now I would like to implement it for setting, i.e.: `risc[1] = 2`.

How can it be done?

Overload bracket operators [] to get and set

I know this question has been asked several times, but none of them have a real answer for a workaround. Maybe there&#39;s one for my specific case.

I&#39;m building a mapper class which uses the magic method `__get()` to lazy load other objects. It looks something like this:

    public function __get ( $index )
    {
        if ( isset ($this-&gt;vars[$index]) )
        {
            return $this-&gt;vars[$index];
        }
        
        // $index = &#39;role&#39;;
        $obj = $this-&gt;createNewObject ( $index );
    
        return $obj;
    }

In my code I do:

    $user = createObject(&#39;user&#39;);
    $user-&gt;role-&gt;rolename;

This works so far. The `User` object doesn&#39;t have a property called &#39;role&#39;, so it uses the magic `__get()` method to create that object and it returns its property from the &#39;role&#39; object.

But when i try to modify the &#39;rolename&#39;:

    $user = createUser();
    $user-&gt;role-&gt;rolename = &#39;Test&#39;;

Then it gives me the following error:

&gt; **Notice: Indirect modification of overloaded property has no effect**

Not sure if this is still some bug in PHP or if it&#39;s &quot;expected behaviour&quot;, but in any case it doesn&#39;t work the way I want. This is really a show stopper for me... Because how on earth am I able to change the properties of the lazy loaded objects??

-----

EDIT:

The actual problem only seems to occur when I return an array which contains multiple objects.

I&#39;ve added an example piece of code which reproduces the problem:

http://codepad.org/T1iPZm9t

You should really run this in your PHP environment the really see the &#39;error&#39;. But there is something really interesting going on here.

I try to change the property of an object, which gives me the notice &#39;cant change overloaded property&#39;. But if I echo the property after that I see that it actually DID change the value... Really weird...

PHP - Indirect modification of overloaded property

Is there a magic method that can overload the assignment operator, like `__assign__(self, new_value)`?

I&#39;d like to forbid a re-bind for an instance:

    class Protect():
      def __assign__(self, value):
        raise Exception(&quot;This is an ex-parrot&quot;)

    var = Protect()  # once assigned...
    var = 1          # this should raise Exception()

Is it possible? Is it insane? Should I be on medicine?

Is it possible to overload Python assignment?

I try to understand some Slick works and what it requires.

Here it an example:


    package models

    case class Bar(id: Option[Int] = None, name: String)
    
    object Bars extends Table[Bar](&quot;bar&quot;) {
      def id = column[Int](&quot;id&quot;, O.PrimaryKey, O.AutoInc)
    
      // This is the primary key column
      def name = column[String](&quot;name&quot;)
    
      // Every table needs a * projection with the same type as the table&#39;s type parameter
      def * = id.? ~ name &lt;&gt;(Bar, Bar.unapply _)
    }

Could somebody explain me what&#39;s the purpose of `*` method here, what is `&lt;&gt;`, why `unapply`? and what is Projection - method `~`&#39; returns the instance of `Projection2`?


scala slick method I can not understand so far

After many happy years coding in notepad++ and sublime, I&#39;ve been advised to give a PHP IDE a go. I&#39;m trying out phpStorm and it seems nice.  The code completion and documentation is a great feature but isn&#39;t working out for me when magic methods are used. **Is there a work around to get phpStorm to understand what&#39;s going on in magic methods?**

Our situation is something like this:

    abstract class a {
        public static function __callStatic($method,$args)
        {
            if(strpos($method,&quot;get_by_&quot;) === 0)
            {
      	        //do stuff
            } elseif(strpos($method,&quot;get_first_by_&quot;) === 0) {
                //do stuff
    	    } elseif($method == &quot;get_all&quot;) {
                //do stuff
            }
        }
    }

    class b extends a {
        // some more stuff
    }
    
    b::get_by_user_id(27);
    b::get_first_by_id(156);
    b::get_all();

The magic callStatic method allows us to get a collection of objects via 1 or more arguments that make up the function call.

I see that there is an @method statement for use in these cases but phpStorm is only picking up the first of these statements. Furthermore I can only set the return type to mixed where as I&#39;d prefer to be able to set it as whatever class this was called on (b in my example).

Any ideas or suggestions would be very gratefully received, thanks.

Content Type	Original Author	Original Content on Stackoverflow
Question	dividebyzero	View Question on Stackoverflow
Solution 1 - Python	Sven Marnach	View Answer on Stackoverflow

How to overload Python's bool method?

Python Problem Overview

Python Solutions

Solution 1 - Python

Eclipse - how to remove light bulb on warnings

Delete Sheets and avoid Excel asking the user to confirm, using custom messages instead

Attributions