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How do I parse a string to a float or int?
...temptible lie
False True So false it becomes true
"123.456" True Decimal
" -127 " True Spaces trimmed
"\t\n12\r\n" True whitespace ignored
"NaN" True Not a number
"NaNanananaBATMAN" False ...
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...
http HEAD vs GET performance
...EAD might work nicely.
For example, suppose you want to check if resource 123 exists. A 200 means "yes" and a 404 means "no":
HEAD /resources/123 HTTP/1.1
[...]
HTTP/1.1 404 Not Found
[...]
However, if the "yes" or "no" you want from your REST service is a part of the resource itself, rather th...
jQuery Data vs Attr?
...you'll need to use .attr():
HTML:
<a id="foo" href="#" data-color="ABC123"></a>
<a id="bar" href="#" data-color="654321"></a>
JS:
$('#foo').data('color').length; //6
$('#bar').data('color').length; //undefined, length isn't a property of numbers
$('#foo').attr('data-col...
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 ...
How do I perform an insert and return inserted identity with Dapper?
...Username = "lorem ipsum",
Phone = "555-123",
Email = "lorem ipsum"
},
tran);
Return inserted object with ID:
If you wanted you could get Phone and Email or even th...
Strangest language feature
...
Or, more usefully, "0123456789abcdef"[x & 0xf]
– Dipstick
Jan 3 '10 at 15:33
17
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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...
How to read a file in reverse order?
...
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
...