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Reference — What does this symbol mean in PHP?
... have the same results.
Pre-increment is a little bit faster because it really increments the variable and after that 'returns' the result. Post-increment creates a special variable, copies there the value of the first variable and only after the first variable is used, replaces its value with seco...
Command-line Unix ASCII-based charting / plotting tool
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While gnuplot is powerful, it's also really irritating when you just want to pipe in a bunch of points and get a graph.
Thankfully, someone created eplot (easy plot), which handles all the nonsense for you.
It doesn't seem to have an option to force terminal gra...
How do I show the value of a #define at compile-time?
...ring. When there is more than one component to the argument then they must all be strings so that string concatenation can be applied. The preprocessor can never assume that an unquoted string should be treated as if it were quoted. If it did then:
#define ABC 123
int n = ABC;
would not compile.
...
How can I force division to be floating point? Division keeps rounding down to 0?
... a floating point number in Python in the following?
c = a / b
What is really being asked here is:
"How do I force true division such that a / b will return a fraction?"
Upgrade to Python 3
In Python 3, to get true division, you simply do a / b.
>>> 1/2
0.5
Floor division, the classic di...
Rails raw SQL example
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and then you'd need to call values on this PG::Result object to get the results array
– jobwat
Mar 26 '14 at 1:00
3
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Getting the names of all files in a directory with PHP
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Not all filenames have the form *.*: just use * instead.
– jameshfisher
Feb 24 '14 at 17:17
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How to add an integer to each element in a list?
...ition, but if you have a more complex function that you needed to apply to all the elements then map may be a good fit.
In your example it would be:
>>> map(lambda x:x+1, [1,2,3])
[2,3,4]
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Encoding an image file with base64
... here is an update after you have edited your original question.
First of all, remember to use raw strings (prefix the string with 'r') when using path delimiters on Windows, to prevent accidentally hitting an escape character. Second, PIL's Image.open either accepts a filename, or a file-like (tha...
Why use strict and warnings?
...tify how much it helps. It should suffice to say that they help unconditionally.
– ikegami
Nov 6 '11 at 19:42
1
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In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
...ents that are passed by reference (id *) and are autoreleased on return.
All of this is very well explained in the ARC transition guide.
In your NSError example, the declaration means __strong, implicitly:
NSError * e = nil;
Will be transformed to:
NSError * __strong error = nil;
When you c...