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When splitting an empty string in Python, why does split() return an empty list while split('\n') re
...ncorporates both splitting algorithms in the same tool.
People seem to mentally model field-splitting
as a single concept even though more than one algorithm is involved.
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List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
How do you iterate through every file/directory recursively in standard C++?
...e to the standard.
An example, taken straight from the website:
bool find_file( const path & dir_path, // in this directory,
const std::string & file_name, // search for this name,
path & path_found ) // placing path here if found
{
...
How to check if an email address exists without sending an email?
...here are two methods you can sometimes use to determine if a recipient actually exists:
You can connect to the server, and issue a VRFY command. Very few servers support this command, but it is intended for exactly this. If the server responds with a 2.0.0 DSN, the user exists.
VRFY user
You can...
onCreateOptionsMenu inside Fragments
...nsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_sample, menu);
super.onCreateOptionsMenu(menu,inflater);
}
And in onCreate add this line to make the options appear in your Toolbar
setHasOptionsMenu(true);
...
Detecting a mobile browser
...
@RichardLovejoy when building sites, the ipad is generally not considered a mobile.
– Michael Zaporozhets
Mar 28 '13 at 11:14
43
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Best way to implement Enums with Core Data
...to assign a type property to the entity? In other words, I have an entity called Item with an itemType property that I want to be bound to an enum, what is the best way of going about this.
...
Can I have onScrollListener for a ScrollView?
...
Every instance of View calls getViewTreeObserver(). Now when holding an instance of ViewTreeObserver, you can add an OnScrollChangedListener() to it using the method addOnScrollChangedListener().
You can see more information about this class here.
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Is there a way to make mv create the directory to be moved to if it doesn't exist?
...ectories don't exist, is there some way to have those directories automatically created, so that you would only have to type
...
MongoDB drop every database
..."dropping db " + db.getName() );
db.dropDatabase();
}
save it to dropall.js and then execute:
mongo dropall.js
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