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Convert string in base64 to image and save on filesystem in Python
I have a string in base64 format, which represents PNG image. Is there a way to save this image to the filesystem, as a PNG file?
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What is the most elegant way to remove a path from the $PATH variable in Bash?
Or more generally, how do I remove an item from a colon-separated list in a Bash environment variable?
33 Answers
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Effects of the extern keyword on C functions
In C, I did not notice any effect of the extern keyword used before function declaration.
At first, I thought that when defining extern int f(); in a single file forces you to implement it outside of the file's scope. However I found out that both:
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Replace multiple characters in a C# string
...te through the array of characters the least amount of times. Note the HashSet here, as it avoids to traverse the character sequence inside the loop. Should you need an even faster lookup, you can replace HashSet by an optimized lookup for char (based on an array[256]).
Example with StringBuilder
pu...
C++ SFINAE examples?
...ompared to the other implementations, this one is fairly simple: a reduced set of tools (void_t and detect) suffices. Besides, it was reported (see N4502) that it is measurably more efficient (compile-time and compiler memory consumption) than previous approaches.
Here is a live example, which inc...
How to modify existing, unpushed commit messages?
...change the commit message of the most recent commit. Additionally, you can set the commit message directly in the command line with:
git commit --amend -m "New commit message"
…however, this can make multi-line commit messages or small corrections more cumbersome to enter.
Make sure you don't hav...
What's the absurd function in Data.Void useful for?
...f bad behaviour uniformly. For perfectly well behaved computations in this setting, take e to be Void, then use
either absurd id :: Either Void v -> v
to run safely or
either absurd Right :: Either Void v -> Either e v
to embed safe components in an unsafe world.
Oh, and one last hurrah...
Extracting bits with a single multiplication
... something that a theorem prover can understand, namely SMT-LIB 2 input:
(set-logic BV)
(declare-const mask (_ BitVec 64))
(declare-const multiplicand (_ BitVec 64))
(assert
(forall ((x (_ BitVec 64)))
(let ((y (bvmul (bvand mask x) multiplicand)))
(and
(= ((_ extract ...
How to 'bulk update' with Django?
...o signals will be emitted.
You can't perform an .update() on a sliced QuerySet, it must be on an original QuerySet so you'll need to lean on the .filter() and .exclude() methods.
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Convert character to ASCII code in JavaScript
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edited Feb 6 '17 at 12:11
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