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PHP method chaining?
...g PHP 5 and I've heard of a new featured in the object-oriented approach, called 'method chaining'. What is it exactly? How do I implement it?
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Why can't yield return appear inside a try block with a catch?
...ty. I suspect there are very, very few times where this restriction is actually an issue that can't be worked around - but the added complexity in the compiler would be very significant.
There are a few things like this that I've already encountered:
Attributes not being able to be generic
Inabil...
What's the difference between eval, exec, and compile?
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The short answer, or TL;DR
Basically, eval is used to evaluate a single dynamically generated Python expression, and exec is used to execute dynamically generated Python code only for its side effects.
eval and exec have these two differences:
eval accep...
Can I convert long to int?
...ew Random() uses Environment.TickCount under the hood; no need to seed manually with clock ticks.
– Mehrdad Afshari
Oct 8 '11 at 22:51
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In Python script, how do I set PYTHONPATH?
... that if you want to make sure that Python checks the new directory before all of the others when importing, you should put the new directory first in the list, as in sys.path.insert(0, '/path/to/whatever').
– wecsam
Jun 15 '17 at 16:22
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How to write the Fibonacci Sequence?
I had originally coded the program wrongly. Instead of returning the Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 should = only those numbers between 1 & 20), I have written for the program to display all Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 displa...
Instance variables vs. class variables in Python
...r instance. If there would be more than one instance (which won't happen), all instance should have the same configuration. I wonder which of the following options would be better or more "idiomatic" Python.
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How can I update NodeJS and NPM to the next versions?
I just installed Node.js and npm (for additional modules).
47 Answers
47
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How can I use if/else in a dictionary comprehension?
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@Marcin's answer covers it all, but just in case someone wants to see an actual example, I add two below:
Let's say you have the following dictionary of sets
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
and you want ...
How to change XAMPP apache server port?
...a free port number
The default port used by Apache is 80.
Take a look to all your used ports with Netstat (integrated to XAMPP Control Panel).
Then you can see all used ports and here we see that the 80port is already used by System.
Choose a free port number (8012, for this exemple).
2. Ed...