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Why are variables “i” and “j” used for counters?
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It comes ultimately from mathematics: the summation notation traditionally uses i for the first index, j for the second, and so on. Example (from http://en.wikipedia.org/wiki/Summation):
It's also used that way for collections of things,...
Array slices in C#
...o = new byte[4096];
var bar = foo.Take(41);
If you really need an array from any IEnumerable<byte> value, you could use the ToArray() method for that. That does not seem to be the case here.
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Swift days between two NSDates
...let flags = NSCalendarUnit.Day
let components = calendar.components(flags, fromDate: date1, toDate: date2, options: [])
components.day // This will return the number of day(s) between dates
Swift 3 and Swift 4 Version
let calendar = Calendar.current
// Replace the hour (time) of both dates wit...
Python circular importing?
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The easiest way to do so is to use import my_module syntax, rather than from my_module import some_object. The former will almost always work, even if my_module included imports us back. The latter only works if my_object is already defined in my_module, which in a circular import may not be the ...
Project structure for Google App Engine
...ion.
Here I'll post a slightly modified version of the layout/structure from that page. I pretty much follow this pattern myself. You also mentioned you had trouble with packages. Just make sure each of your sub folders has an __init__.py file. It's ok if its empty.
Boilerplate files
These har...
How to replace (or strip) an extension from a filename in Python?
...how to remove an extension using pathlib (Python >= 3.4):
>>> from pathlib import Path
>>> filename = Path('/some/path/somefile.txt')
>>> filename_wo_ext = filename.with_suffix('')
>>> filename_replace_ext = filename.with_suffix('.jpg')
>>> print(...
How to install packages using pip according to the requirements.txt file from a local directory?
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Information on --no-index from command pip help install --no-index Ignore package index (only looking at --find-links URLs instead). Information on --find-links from command pip help install -f, --find-links <url> If a url or path to an html f...
How to delete SQLite database from Android programmatically
I would like to delete the database file from the Android file system programatically? Can I have a shell script launch adb which in turns runs a shell script in the Android space to do the database deletion? Can I get this done from within a JUnit test case (with a system() call)?
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Removing items from a list [duplicate]
... might throw an UnsupportedOperationException if you have your list formed from Arrays.asList(arr) because Arrays.asList() gives you a fixed list. In that case, do an List<E> myList = new ArrayList<>(Arrays.asList(arr)) and then use the listIterator over the list. Same goes if you want t...
“Inner exception” (with traceback) in Python?
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Python 3 adds raise E() from tb and .with_traceback(...)
– Dima Tisnek
May 30 '14 at 9:02
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