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How do you remove duplicates from a list whilst preserving order?
...o seen_add instead of just calling seen.add? Python is a dynamic language, and resolving seen.add each iteration is more costly than resolving a local variable. seen.add could have changed between iterations, and the runtime isn't smart enough to rule that out. To play it safe, it has to check the o...
MySQL foreign key constraints, cascade delete
I want to use foreign keys to keep the integrity and avoid orphans (I already use innoDB).
3 Answers
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Why do we use arrays instead of other data structures?
...gured the added "features" in programming languages had improved upon this and by that replaced them. I see now that they aren't replaced but rather given new life, so to speak.
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Git ignore sub folders
...t of projects in my .Net solution. I would like to exclude all "bin/Debug" and "bin/Release" folders (and their contents), but still include the "bin" folder itself and any dll's contained therein.
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&& (AND) and || (OR) in IF statements
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No, it will not be evaluated. And this is very useful. For example, if you need to test whether a String is not null or empty, you can write:
if (str != null && !str.isEmpty()) {
doSomethingWith(str.charAt(0));
}
or, the other way around
if ...
Singleton pattern in nodejs - is it needed?
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This has basically to do with nodejs caching. Plain and simple.
https://nodejs.org/api/modules.html#modules_caching
(v 6.3.1)
Caching
Modules are cached after the first time they are loaded. This means
(among other things) that every call to require('foo') will ge...
Python list subtraction operation
...set(x) - set(y))
>>> z
[0, 8, 2, 4, 6]
Or you might just have x and y be sets so you don't have to do any conversions.
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Separate Back Stack for each tab in Android using Fragments
I'm trying to implement tabs for navigation in an Android app. Since TabActivity and ActivityGroup are deprecated I would like to implement it using Fragments instead.
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Custom bullet symbol for elements in that is a regular character, and not an image
...ides a straightforward solution. Simply add list-style: none; to your rule and force the LIs to display with hanging indents. The rule will look something like this:
ul {
list-style: none;
margin-left: 0;
padding-left: 1em;
text-indent: -1em;
}
Either the padding or the margin needs to ...
“CAUTION: provisional headers are shown” in Chrome debugger
...r Latest Versions of chrome
Type chrome://net-export/ in the address bar and hit enter.
Start Recording. And save Recording file to local.
Open the page that is showing problems.
Go back to net-internals
You can view Recorded Log file Here https://netlog-viewer.appspot.com/#import
click on events ...