From Python 2.5 onwards you can do:

    value = b if a &gt; 10 else c

Previously you would have to do something like the following, although the semantics isn&#39;t identical as the short circuiting effect is lost:

    value = [c, b][a &gt; 10]

There&#39;s also another hack using &#39;and ... or&#39; but it&#39;s best to not use it as it has an undesirable behaviour in some situations that can lead to a hard to find bug. I won&#39;t even write the hack here as I think it&#39;s best not to use it, but you can read about it on [Wikipedia][1] if you want.

[1]: http://en.wikipedia.org/wiki/%3F:#Python

simple is the best and works in every version.

    if a&gt;10: 
        value=&quot;b&quot;
    else: 
        value=&quot;c&quot;

I need to parse following String into a DateTime Object:&lt;br&gt;
`30/Nov/2009:16:29:30 +0100`

Is there an easy way to do this?

*PS:* I want to convert the string above as is. The colon after the year is not a typo. I also want to solve the problem with Ruby and not RoR.

convert String to DateTime

Is it possible to use CSS to disable autocomplete on a form element (specifically a textfield)?

I use a tag library which does not permit the autocomplete element and I would like to disable autocomplete without using Javascript.

Disable autocomplete via CSS

do you know if Python supports some keyword or expression like in C++ to return values based on `if` condition, all in the same line (The C++ `if` expressed with the question mark `?`)

    // C++
    value = ( a &gt; 10 ? b : c )

Conditional operator in Python?

do you know if Python supports some keyword or expression like in C++ to return values based on <code>if</code> condition, all in the same line (The C++ <code>if</code> expressed with the question mark <code>?</code>)
<pre><code class="hljs language-css">// C++
value = ( a > 10 ? b : c )
</code></pre>

I&#39;ve just upgraded from Python 2.6.1 to 2.6.4 on my development machine and upon starting a python script was presented with the following message:

&gt; Can&#39;t extract file(s) to egg cache
&gt; 
&gt; The following error occurred while
&gt; trying to extract file(s) to  the
&gt; Python egg cache:
&gt; 
&gt; [Errno 13] Permission denied:
&gt; &#39;/var/www/.python-eggs&#39;
&gt; 
&gt; The Python egg cache directory is
&gt; currently set to:
&gt; 
&gt; /var/www/.python-eggs
&gt; 
&gt; Perhaps your account does not have
&gt; write access to this directory?   You
&gt; can change the cache directory by
&gt; setting the PYTHON_EGG_CACHE 
&gt; environment variable to point to an
&gt; accessible directory.

There isn&#39;t anything in the [python docs][1] so I&#39;m at a bit of a loss regarding best-practices on where to put this directory and what it&#39;s used for.

Can someone explain what the Python egg cache is?

Also, can you explain why/how it is different to the `site-packages` directory Python uses to store eggs (as I understand it)?


  [1]: http://docs.python.org/search.html?q=PYTHON_EGG_CACHE&amp;check_keywords=yes&amp;area=default

What is the Python egg cache (PYTHON_EGG_CACHE)?

What is the upper level exception that I can catch SQLAlechmy exceptions with ?

    &gt;&gt;&gt; from sqlalchemy import exc
    &gt;&gt;&gt; dir(exc)
    [&#39;ArgumentError&#39;, &#39;CircularDependencyError&#39;, &#39;CompileError&#39;, &#39;ConcurrentModificationError&#39;, &#39;DBAPIError&#39;, &#39;DataError&#39;, &#39;DatabaseError&#39;, &#39;DisconnectionError&#39;, &#39;FlushError&#39;, &#39;IdentifierError&#39;, &#39;IntegrityError&#39;, &#39;InterfaceError&#39;, &#39;InternalError&#39;, &#39;InvalidRequestError&#39;, &#39;NoReferenceError&#39;, &#39;NoReferencedColumnError&#39;, &#39;NoReferencedTableError&#39;, &#39;NoSuchColumnError&#39;, &#39;NoSuchTableError&#39;, &#39;NotSupportedError&#39;, &#39;OperationalError&#39;, &#39;ProgrammingError&#39;, &#39;SADeprecationWarning&#39;, &#39;SAPendingDeprecationWarning&#39;, &#39;SAWarning&#39;, &#39;SQLAlchemyError&#39;, &#39;SQLError&#39;, &#39;TimeoutError&#39;, &#39;UnboundExecutionError&#39;, &#39;UnmappedColumnError&#39;, &#39;__builtins__&#39;, &#39;__doc__&#39;, &#39;__file__&#39;, &#39;__name__&#39;, &#39;__package__&#39;]
    &gt;&gt;&gt; 



catching SQLAlchemy exceptions

What is the point of `&#39;/segment/segment/&#39;.split(&#39;/&#39;)` returning `[&#39;&#39;, &#39;segment&#39;, &#39;segment&#39;, &#39;&#39;]`?

Notice the empty elements. If you&#39;re splitting on a delimiter that happens to be at position one and at the very end of a string, what extra value does it give you to have the empty string returned from each end?


Why are empty strings returned in split() results?

In a comment on [this question][1], I saw a statement that recommended using

    result is not None
vs

    result != None

I was wondering what the difference is, and why one might be recommended over the other?

  [1]: https://stackoverflow.com/questions/2079786/caching-sitemaps-in-django

Python != operation vs &quot;is not&quot;

This is not a homework, I am just curious.

INFINITE is the key word here.

I wish to use it as `for p in primes()`. I believe that this is a built-in function in Haskell.

So, the answer cannot be as naive as &quot;Just do a Sieve&quot;.

First of all, you do not know how many consecutive primes will be consumed. Well, suppose you could concoct 100 of them at a time. Would you use the same Sieve approach as well as the frequency of prime numbers formula?

I prefer non-concurrent approach.

Thank you for reading (and writing ;) )!


How to implement an efficient infinite generator of prime numbers in Python?

What is the best way to guard against null in a for loop in Java? 

This seems ugly :

    if (someList != null) {
        for (Object object : someList) {
            // do whatever
        }
    }

Or

    if (someList == null) {
        return; // Or throw ex
    }
    for (Object object : someList) {
        // do whatever
    }

There might not be any other way. Should they have put it in the `for` construct itself, if it is null then don&#39;t run the loop?

Null check in an enhanced for loop

I am intrigued by the following python expression:

    d3 = dict(d1, **d2)

The task is to merge 2 dictionaries into a third one, and the above expression accomplishes the task just fine. I am interested in the ** operator and what exactly is it doing to the expression. I thought that ** was the power operator and haven&#39;t seen it used in the context above yet.

The full snippet of code is this:

    &gt;&gt;&gt; d1 = {&#39;a&#39;: 1, &#39;b&#39;: 2}
    &gt;&gt;&gt; d2 = {&#39;c&#39;: 3, &#39;d&#39;: 4}
    &gt;&gt;&gt; d3 = dict(d1, **d2)
    &gt;&gt;&gt; print d3
    {&#39;a&#39;: 1, &#39;c&#39;: 3, &#39;b&#39;: 2, &#39;d&#39;: 4}

What does `**` mean in the expression `dict(d1, **d2)`?

I have this script called test.sh:

    #!/bin/bash
    STR = &quot;Hello World&quot;
    echo $STR

when I run `sh test.sh` I get this:

    test.sh: line 2: STR: command not found

What am I doing wrong?  I look at extremely basic/beginners bash scripting tutorials online and this is how they say to declare variables... So I&#39;m not sure what I&#39;m doing wrong.

I&#39;m on Ubuntu Server 9.10. And yes, bash is located at `/bin/bash`.

Command not found error in Bash variable assignment

I just stumbled upon something in ORACLE SQL (not sure if it&#39;s in others), that I am curious about. I am asking here as a wiki, since it&#39;s hard to try to search symbols in google... 

I just found that when checking a value against a set of values you can do 

    WHERE x = ANY (a, b, c)

As opposed to the usual 

    WHERE x IN (a, b, c)

So I&#39;m curious, what is the reasoning for these two syntaxes? Is one **standard** and one some oddball Oracle syntax? Or are they both standard? And is there a preference of one over the other for performance reasons, or ? 

Just curious what anyone can tell me about that &#39;= ANY&#39; syntax. 
CheerZ!

Oracle: &#39;= ANY()&#39; vs. &#39;IN ()&#39;

How do I make Python dictionary members accessible via a dot &quot;.&quot;?

For example, instead of writing `mydict[&#39;val&#39;]`, I&#39;d like to write `mydict.val`.

Also I&#39;d like to access nested dicts this way. For example

    mydict.mydict2.val 

would refer to 

    mydict = { &#39;mydict2&#39;: { &#39;val&#39;: ... } }

Content Type	Original Author	Original Content on Stackoverflow
Question	Abruzzo Forte e Gentile	View Question on Stackoverflow
Solution 1 - Python	Mark Byers	View Answer on Stackoverflow
Solution 2 - Python	ghostdog74	View Answer on Stackoverflow

Conditional operator in Python?

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Disable autocomplete via CSS

convert String to DateTime

Attributions