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Difference between malloc and calloc?
..., while malloc() leaves the memory uninitialized.
For large allocations, most calloc implementations under mainstream OSes will get known-zeroed pages from the OS (e.g. via POSIX mmap(MAP_ANONYMOUS) or Windows VirtualAlloc) so it doesn't need to write them in user-space. This is how normal malloc ...
In Python script, how do I set PYTHONPATH?
...
It has been many years since this answer was posted, but I still want to add that if you want to make sure that Python checks the new directory before all of the others when importing, you should put the new directory first in the list, as in sys.path.insert(0, '/path/to...
Negation in Python
...herefore just replace your ! with not.
For your example, do this:
if not os.path.exists("/usr/share/sounds/blues") :
proc = subprocess.Popen(["mkdir", "/usr/share/sounds/blues"])
proc.wait()
For your specific example (as Neil said in the comments), you don't have to use the subprocess ...
What is the behavior difference between return-path, reply-to and from?
...mpany.com>
Subject: Super simple email
Reply-To: <coolstuff-threadId=123@mymailinglist.com>
This is a very simple body.
Now, let's say you are going to send it from a mailing list, that implements VERP (or some other bounce tracking mechanism that uses a different return-path). Lets sa...
REST authentication and exposing the API key
...eed REFERER. Still, it is secure:
When our get-csrf-token.js?apiKey=abc123 is requested:
Look up the key abc123 in the database and get a list of valid domains for that key.
Look for the CSRF validation cookie. If it does not exist, generate a secure random value and put it in a HTTP-only sess...
Two-dimensional array in Swift
... = 18
OR
let myVar = 18
arr[0][1] = myVar
Change sub array
arr[1] = [123, 456, 789]
OR
arr[0] += 234
OR
arr[0] += [345, 678]
If you had 3x2 array of 0(zeros) before these changes, now you have:
[
[0, 0, 234, 345, 678], // 5 elements!
[123, 456, 789],
[0, 0]
]
So be aware tha...
How can I programmatically determine if my app is running in the iphone simulator?
...r "Compiling source code conditionally"
The relevant definition is TARGET_OS_SIMULATOR, which is defined in /usr/include/TargetConditionals.h within the iOS framework. On earlier versions of the toolchain, you had to write:
#include "TargetConditionals.h"
but this is no longer necessary on the c...
Why is a combiner needed for reduce method that converts type in java 8
... answered Sep 4 '15 at 7:39
quiz123quiz123
3655 bronze badges
...
How to read a file in reverse order?
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Also, while the posted code does answer the question, we should be careful to close files that we open. The with statement is usually quite painless.
– William
Mar 7 '13 at 14:41
...
How to generate all permutations of a list?
...
Combination (order does NOT matter):
print list(itertools.combinations('123', 2))
[('1', '2'), ('1', '3'), ('2', '3')]
Cartesian product (with several iterables):
print list(itertools.product([1,2,3], [4,5,6]))
[(1, 4), (1, 5), (1, 6),
(2, 4), (2, 5), (2, 6),
(3, 4), (3, 5), (3, 6)]
Cartesia...